Algebra Examples

Find the Inverse f(x) = cube root of 8x+4
Step 1
Write as an equation.
Step 2
Interchange the variables.
Step 3
Solve for .
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Step 3.1
Rewrite the equation as .
Step 3.2
Subtract from both sides of the equation.
Step 3.3
To remove the radical on the left side of the equation, cube both sides of the equation.
Step 3.4
Simplify each side of the equation.
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Step 3.4.1
Use to rewrite as .
Step 3.4.2
Simplify the left side.
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Step 3.4.2.1
Simplify .
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Step 3.4.2.1.1
Multiply the exponents in .
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Step 3.4.2.1.1.1
Apply the power rule and multiply exponents, .
Step 3.4.2.1.1.2
Cancel the common factor of .
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Step 3.4.2.1.1.2.1
Cancel the common factor.
Step 3.4.2.1.1.2.2
Rewrite the expression.
Step 3.4.2.1.2
Simplify.
Step 3.4.3
Simplify the right side.
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Step 3.4.3.1
Simplify .
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Step 3.4.3.1.1
Use the Binomial Theorem.
Step 3.4.3.1.2
Simplify each term.
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Step 3.4.3.1.2.1
Multiply by .
Step 3.4.3.1.2.2
Raise to the power of .
Step 3.4.3.1.2.3
Multiply by .
Step 3.4.3.1.2.4
Raise to the power of .
Step 3.5
Divide each term in by and simplify.
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Step 3.5.1
Divide each term in by .
Step 3.5.2
Simplify the left side.
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Step 3.5.2.1
Cancel the common factor of .
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Step 3.5.2.1.1
Cancel the common factor.
Step 3.5.2.1.2
Divide by .
Step 3.5.3
Simplify the right side.
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Step 3.5.3.1
Simplify each term.
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Step 3.5.3.1.1
Cancel the common factor of and .
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Step 3.5.3.1.1.1
Factor out of .
Step 3.5.3.1.1.2
Cancel the common factors.
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Step 3.5.3.1.1.2.1
Factor out of .
Step 3.5.3.1.1.2.2
Cancel the common factor.
Step 3.5.3.1.1.2.3
Rewrite the expression.
Step 3.5.3.1.2
Move the negative in front of the fraction.
Step 3.5.3.1.3
Cancel the common factor of and .
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Step 3.5.3.1.3.1
Factor out of .
Step 3.5.3.1.3.2
Cancel the common factors.
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Step 3.5.3.1.3.2.1
Factor out of .
Step 3.5.3.1.3.2.2
Cancel the common factor.
Step 3.5.3.1.3.2.3
Rewrite the expression.
Step 3.5.3.1.3.2.4
Divide by .
Step 3.5.3.1.4
Divide by .
Step 4
Replace with to show the final answer.
Step 5
Verify if is the inverse of .
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Step 5.1
To verify the inverse, check if and .
Step 5.2
Evaluate .
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Step 5.2.1
Set up the composite result function.
Step 5.2.2
Evaluate by substituting in the value of into .
Step 5.2.3
Simplify each term.
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Step 5.2.3.1
Simplify the numerator.
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Step 5.2.3.1.1
Use to rewrite as .
Step 5.2.3.1.2
Apply the product rule to .
Step 5.2.3.1.3
Rewrite as .
Step 5.2.3.1.4
Apply the power rule and multiply exponents, .
Step 5.2.3.1.5
Cancel the common factor of .
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Step 5.2.3.1.5.1
Cancel the common factor.
Step 5.2.3.1.5.2
Rewrite the expression.
Step 5.2.3.1.6
Evaluate the exponent.
Step 5.2.3.1.7
Factor out of .
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Step 5.2.3.1.7.1
Factor out of .
Step 5.2.3.1.7.2
Factor out of .
Step 5.2.3.1.7.3
Factor out of .
Step 5.2.3.1.8
Apply the product rule to .
Step 5.2.3.1.9
Raise to the power of .
Step 5.2.3.2
Cancel the common factor.
Step 5.2.3.3
Divide by .
Step 5.2.3.4
Use the Binomial Theorem.
Step 5.2.3.5
Simplify each term.
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Step 5.2.3.5.1
Multiply the exponents in .
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Step 5.2.3.5.1.1
Apply the power rule and multiply exponents, .
Step 5.2.3.5.1.2
Cancel the common factor of .
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Step 5.2.3.5.1.2.1
Cancel the common factor.
Step 5.2.3.5.1.2.2
Rewrite the expression.
Step 5.2.3.5.2
Simplify.
Step 5.2.3.5.3
Multiply the exponents in .
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Step 5.2.3.5.3.1
Apply the power rule and multiply exponents, .
Step 5.2.3.5.3.2
Combine and .
Step 5.2.3.5.4
Multiply by .
Step 5.2.3.5.5
Raise to the power of .
Step 5.2.3.5.6
Multiply by .
Step 5.2.3.5.7
Raise to the power of .
Step 5.2.3.6
Simplify the numerator.
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Step 5.2.3.6.1
Use to rewrite as .
Step 5.2.3.6.2
Apply the product rule to .
Step 5.2.3.6.3
Rewrite as .
Step 5.2.3.6.4
Apply the power rule and multiply exponents, .
Step 5.2.3.6.5
Cancel the common factor of .
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Step 5.2.3.6.5.1
Cancel the common factor.
Step 5.2.3.6.5.2
Rewrite the expression.
Step 5.2.3.6.6
Evaluate the exponent.
Step 5.2.3.6.7
Factor out of .
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Step 5.2.3.6.7.1
Factor out of .
Step 5.2.3.6.7.2
Factor out of .
Step 5.2.3.6.7.3
Factor out of .
Step 5.2.3.6.8
Apply the product rule to .
Step 5.2.3.6.9
Raise to the power of .
Step 5.2.3.6.10
Multiply by .
Step 5.2.3.7
Factor out of .
Step 5.2.3.8
Cancel the common factors.
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Step 5.2.3.8.1
Factor out of .
Step 5.2.3.8.2
Cancel the common factor.
Step 5.2.3.8.3
Rewrite the expression.
Step 5.2.3.8.4
Divide by .
Step 5.2.3.9
Rewrite as .
Step 5.2.3.10
Expand using the FOIL Method.
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Step 5.2.3.10.1
Apply the distributive property.
Step 5.2.3.10.2
Apply the distributive property.
Step 5.2.3.10.3
Apply the distributive property.
Step 5.2.3.11
Simplify and combine like terms.
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Step 5.2.3.11.1
Simplify each term.
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Step 5.2.3.11.1.1
Multiply by by adding the exponents.
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Step 5.2.3.11.1.1.1
Use the power rule to combine exponents.
Step 5.2.3.11.1.1.2
Combine the numerators over the common denominator.
Step 5.2.3.11.1.1.3
Add and .
Step 5.2.3.11.1.2
Move to the left of .
Step 5.2.3.11.1.3
Multiply by .
Step 5.2.3.11.2
Add and .
Step 5.2.3.12
Apply the distributive property.
Step 5.2.3.13
Simplify.
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Step 5.2.3.13.1
Multiply by .
Step 5.2.3.13.2
Multiply by .
Step 5.2.3.14
Apply the distributive property.
Step 5.2.3.15
Simplify.
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Step 5.2.3.15.1
Multiply by .
Step 5.2.3.15.2
Multiply by .
Step 5.2.3.15.3
Multiply by .
Step 5.2.3.16
Simplify each term.
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Step 5.2.3.16.1
Rewrite as .
Step 5.2.3.16.2
Pull terms out from under the radical.
Step 5.2.3.17
Apply the distributive property.
Step 5.2.3.18
Multiply by .
Step 5.2.3.19
Multiply by .
Step 5.2.4
Simplify by adding terms.
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Step 5.2.4.1
Combine the opposite terms in .
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Step 5.2.4.1.1
Subtract from .
Step 5.2.4.1.2
Add and .
Step 5.2.4.1.3
Add and .
Step 5.2.4.1.4
Add and .
Step 5.2.4.1.5
Subtract from .
Step 5.2.4.1.6
Add and .
Step 5.2.4.2
Subtract from .
Step 5.3
Evaluate .
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Step 5.3.1
Set up the composite result function.
Step 5.3.2
Evaluate by substituting in the value of into .
Step 5.3.3
Simplify each term.
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Step 5.3.3.1
To write as a fraction with a common denominator, multiply by .
Step 5.3.3.2
Write each expression with a common denominator of , by multiplying each by an appropriate factor of .
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Step 5.3.3.2.1
Multiply by .
Step 5.3.3.2.2
Multiply by .
Step 5.3.3.3
Combine the numerators over the common denominator.
Step 5.3.3.4
Simplify the numerator.
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Step 5.3.3.4.1
Factor out of .
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Step 5.3.3.4.1.1
Factor out of .
Step 5.3.3.4.1.2
Factor out of .
Step 5.3.3.4.1.3
Factor out of .
Step 5.3.3.4.2
Multiply by .
Step 5.3.3.5
To write as a fraction with a common denominator, multiply by .
Step 5.3.3.6
Combine and .
Step 5.3.3.7
Combine the numerators over the common denominator.
Step 5.3.3.8
Simplify the numerator.
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Step 5.3.3.8.1
Factor out of .
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Step 5.3.3.8.1.1
Factor out of .
Step 5.3.3.8.1.2
Factor out of .
Step 5.3.3.8.1.3
Factor out of .
Step 5.3.3.8.2
Apply the distributive property.
Step 5.3.3.8.3
Multiply by .
Step 5.3.3.8.4
Move to the left of .
Step 5.3.3.8.5
Multiply by .
Step 5.3.3.9
To write as a fraction with a common denominator, multiply by .
Step 5.3.3.10
Combine and .
Step 5.3.3.11
Combine the numerators over the common denominator.
Step 5.3.3.12
Simplify the numerator.
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Step 5.3.3.12.1
Apply the distributive property.
Step 5.3.3.12.2
Simplify.
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Step 5.3.3.12.2.1
Multiply by by adding the exponents.
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Step 5.3.3.12.2.1.1
Multiply by .
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Step 5.3.3.12.2.1.1.1
Raise to the power of .
Step 5.3.3.12.2.1.1.2
Use the power rule to combine exponents.
Step 5.3.3.12.2.1.2
Add and .
Step 5.3.3.12.2.2
Rewrite using the commutative property of multiplication.
Step 5.3.3.12.2.3
Move to the left of .
Step 5.3.3.12.3
Multiply by by adding the exponents.
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Step 5.3.3.12.3.1
Move .
Step 5.3.3.12.3.2
Multiply by .
Step 5.3.3.12.4
Multiply by .
Step 5.3.3.12.5
Rewrite in a factored form.
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Step 5.3.3.12.5.1
Factor using the rational roots test.
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Step 5.3.3.12.5.1.1
If a polynomial function has integer coefficients, then every rational zero will have the form where is a factor of the constant and is a factor of the leading coefficient.
Step 5.3.3.12.5.1.2
Find every combination of . These are the possible roots of the polynomial function.
Step 5.3.3.12.5.1.3
Substitute and simplify the expression. In this case, the expression is equal to so is a root of the polynomial.
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Step 5.3.3.12.5.1.3.1
Substitute into the polynomial.
Step 5.3.3.12.5.1.3.2
Raise to the power of .
Step 5.3.3.12.5.1.3.3
Raise to the power of .
Step 5.3.3.12.5.1.3.4
Multiply by .
Step 5.3.3.12.5.1.3.5
Subtract from .
Step 5.3.3.12.5.1.3.6
Multiply by .
Step 5.3.3.12.5.1.3.7
Add and .
Step 5.3.3.12.5.1.3.8
Subtract from .
Step 5.3.3.12.5.1.4
Since is a known root, divide the polynomial by to find the quotient polynomial. This polynomial can then be used to find the remaining roots.
Step 5.3.3.12.5.1.5
Divide by .
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Step 5.3.3.12.5.1.5.1
Set up the polynomials to be divided. If there is not a term for every exponent, insert one with a value of .
--+-
Step 5.3.3.12.5.1.5.2
Divide the highest order term in the dividend by the highest order term in divisor .
--+-
Step 5.3.3.12.5.1.5.3
Multiply the new quotient term by the divisor.
--+-
+-
Step 5.3.3.12.5.1.5.4
The expression needs to be subtracted from the dividend, so change all the signs in
--+-
-+
Step 5.3.3.12.5.1.5.5
After changing the signs, add the last dividend from the multiplied polynomial to find the new dividend.
--+-
-+
-
Step 5.3.3.12.5.1.5.6
Pull the next terms from the original dividend down into the current dividend.
--+-
-+
-+
Step 5.3.3.12.5.1.5.7
Divide the highest order term in the dividend by the highest order term in divisor .
-
--+-
-+
-+
Step 5.3.3.12.5.1.5.8
Multiply the new quotient term by the divisor.
-
--+-
-+
-+
-+
Step 5.3.3.12.5.1.5.9
The expression needs to be subtracted from the dividend, so change all the signs in
-
--+-
-+
-+
+-
Step 5.3.3.12.5.1.5.10
After changing the signs, add the last dividend from the multiplied polynomial to find the new dividend.
-
--+-
-+
-+
+-
+
Step 5.3.3.12.5.1.5.11
Pull the next terms from the original dividend down into the current dividend.
-
--+-
-+
-+
+-
+-
Step 5.3.3.12.5.1.5.12
Divide the highest order term in the dividend by the highest order term in divisor .
-+
--+-
-+
-+
+-
+-
Step 5.3.3.12.5.1.5.13
Multiply the new quotient term by the divisor.
-+
--+-
-+
-+
+-
+-
+-
Step 5.3.3.12.5.1.5.14
The expression needs to be subtracted from the dividend, so change all the signs in
-+
--+-
-+
-+
+-
+-
-+
Step 5.3.3.12.5.1.5.15
After changing the signs, add the last dividend from the multiplied polynomial to find the new dividend.
-+
--+-
-+
-+
+-
+-
-+
Step 5.3.3.12.5.1.5.16
Since the remander is , the final answer is the quotient.
Step 5.3.3.12.5.1.6
Write as a set of factors.
Step 5.3.3.12.5.2
Factor using the perfect square rule.
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Step 5.3.3.12.5.2.1
Rewrite as .
Step 5.3.3.12.5.2.2
Check that the middle term is two times the product of the numbers being squared in the first term and third term.
Step 5.3.3.12.5.2.3
Rewrite the polynomial.
Step 5.3.3.12.5.2.4
Factor using the perfect square trinomial rule , where and .
Step 5.3.3.12.5.3
Combine like factors.
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Step 5.3.3.12.5.3.1
Raise to the power of .
Step 5.3.3.12.5.3.2
Use the power rule to combine exponents.
Step 5.3.3.12.5.3.3
Add and .
Step 5.3.3.13
Combine and .
Step 5.3.3.14
Reduce the expression by cancelling the common factors.
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Step 5.3.3.14.1
Reduce the expression by cancelling the common factors.
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Step 5.3.3.14.1.1
Cancel the common factor.
Step 5.3.3.14.1.2
Rewrite the expression.
Step 5.3.3.14.2
Divide by .
Step 5.3.3.15
Pull terms out from under the radical, assuming real numbers.
Step 5.3.4
Combine the opposite terms in .
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Step 5.3.4.1
Add and .
Step 5.3.4.2
Add and .
Step 5.4
Since and , then is the inverse of .