Precalculus Examples

Find the Equation with Real Coefficients 48x^3-80x^2+41x-6=0 , x=2/3
,
Step 1
Factor the left side of the equation.
Tap for more steps...
Step 1.1
Factor using the rational roots test.
Tap for more steps...
Step 1.1.1
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 1.1.2
Find every combination of . These are the possible roots of the polynomial function.
Step 1.1.3
Substitute and simplify the expression. In this case, the expression is equal to so is a root of the polynomial.
Tap for more steps...
Step 1.1.3.1
Substitute into the polynomial.
Step 1.1.3.2
Raise to the power of .
Step 1.1.3.3
Multiply by .
Step 1.1.3.4
Raise to the power of .
Step 1.1.3.5
Multiply by .
Step 1.1.3.6
Subtract from .
Step 1.1.3.7
Multiply by .
Step 1.1.3.8
Add and .
Step 1.1.3.9
Subtract from .
Step 1.1.4
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 1.1.5
Divide by .
Tap for more steps...
Step 1.1.5.1
Set up the polynomials to be divided. If there is not a term for every exponent, insert one with a value of .
--+-
Step 1.1.5.2
Divide the highest order term in the dividend by the highest order term in divisor .
--+-
Step 1.1.5.3
Multiply the new quotient term by the divisor.
--+-
+-
Step 1.1.5.4
The expression needs to be subtracted from the dividend, so change all the signs in
--+-
-+
Step 1.1.5.5
After changing the signs, add the last dividend from the multiplied polynomial to find the new dividend.
--+-
-+
-
Step 1.1.5.6
Pull the next terms from the original dividend down into the current dividend.
--+-
-+
-+
Step 1.1.5.7
Divide the highest order term in the dividend by the highest order term in divisor .
-
--+-
-+
-+
Step 1.1.5.8
Multiply the new quotient term by the divisor.
-
--+-
-+
-+
-+
Step 1.1.5.9
The expression needs to be subtracted from the dividend, so change all the signs in
-
--+-
-+
-+
+-
Step 1.1.5.10
After changing the signs, add the last dividend from the multiplied polynomial to find the new dividend.
-
--+-
-+
-+
+-
+
Step 1.1.5.11
Pull the next terms from the original dividend down into the current dividend.
-
--+-
-+
-+
+-
+-
Step 1.1.5.12
Divide the highest order term in the dividend by the highest order term in divisor .
-+
--+-
-+
-+
+-
+-
Step 1.1.5.13
Multiply the new quotient term by the divisor.
-+
--+-
-+
-+
+-
+-
+-
Step 1.1.5.14
The expression needs to be subtracted from the dividend, so change all the signs in
-+
--+-
-+
-+
+-
+-
-+
Step 1.1.5.15
After changing the signs, add the last dividend from the multiplied polynomial to find the new dividend.
-+
--+-
-+
-+
+-
+-
-+
Step 1.1.5.16
Since the remander is , the final answer is the quotient.
Step 1.1.6
Write as a set of factors.
Step 1.2
Factor by grouping.
Tap for more steps...
Step 1.2.1
Factor by grouping.
Tap for more steps...
Step 1.2.1.1
For a polynomial of the form , rewrite the middle term as a sum of two terms whose product is and whose sum is .
Tap for more steps...
Step 1.2.1.1.1
Factor out of .
Step 1.2.1.1.2
Rewrite as plus
Step 1.2.1.1.3
Apply the distributive property.
Step 1.2.1.2
Factor out the greatest common factor from each group.
Tap for more steps...
Step 1.2.1.2.1
Group the first two terms and the last two terms.
Step 1.2.1.2.2
Factor out the greatest common factor (GCF) from each group.
Step 1.2.1.3
Factor the polynomial by factoring out the greatest common factor, .
Step 1.2.2
Remove unnecessary parentheses.
Step 2
If any individual factor on the left side of the equation is equal to , the entire expression will be equal to .
Step 3
Set equal to and solve for .
Tap for more steps...
Step 3.1
Set equal to .
Step 3.2
Solve for .
Tap for more steps...
Step 3.2.1
Add to both sides of the equation.
Step 3.2.2
Divide each term in by and simplify.
Tap for more steps...
Step 3.2.2.1
Divide each term in by .
Step 3.2.2.2
Simplify the left side.
Tap for more steps...
Step 3.2.2.2.1
Cancel the common factor of .
Tap for more steps...
Step 3.2.2.2.1.1
Cancel the common factor.
Step 3.2.2.2.1.2
Divide by .
Step 4
Set equal to and solve for .
Tap for more steps...
Step 4.1
Set equal to .
Step 4.2
Solve for .
Tap for more steps...
Step 4.2.1
Add to both sides of the equation.
Step 4.2.2
Divide each term in by and simplify.
Tap for more steps...
Step 4.2.2.1
Divide each term in by .
Step 4.2.2.2
Simplify the left side.
Tap for more steps...
Step 4.2.2.2.1
Cancel the common factor of .
Tap for more steps...
Step 4.2.2.2.1.1
Cancel the common factor.
Step 4.2.2.2.1.2
Divide by .
Step 5
Set equal to and solve for .
Tap for more steps...
Step 5.1
Set equal to .
Step 5.2
Solve for .
Tap for more steps...
Step 5.2.1
Add to both sides of the equation.
Step 5.2.2
Divide each term in by and simplify.
Tap for more steps...
Step 5.2.2.1
Divide each term in by .
Step 5.2.2.2
Simplify the left side.
Tap for more steps...
Step 5.2.2.2.1
Cancel the common factor of .
Tap for more steps...
Step 5.2.2.2.1.1
Cancel the common factor.
Step 5.2.2.2.1.2
Divide by .
Step 6
The final solution is all the values that make true.
Step 7
Since the roots of an equation are the points where the solution is , set each root as a factor of the equation that equals .
Step 8
Simplify.
Tap for more steps...
Step 8.1
Simplify terms.
Tap for more steps...
Step 8.1.1
Apply the distributive property.
Step 8.1.2
Combine and .
Step 8.2
Simplify each term.
Tap for more steps...
Step 8.2.1
Simplify the numerator.
Tap for more steps...
Step 8.2.1.1
To write as a fraction with a common denominator, multiply by .
Step 8.2.1.2
Combine and .
Step 8.2.1.3
Combine the numerators over the common denominator.
Step 8.2.1.4
Move to the left of .
Step 8.2.2
Move to the left of .
Step 8.2.3
Simplify the numerator.
Tap for more steps...
Step 8.2.3.1
Multiply by each element of the matrix.
Step 8.2.3.2
Simplify each element in the matrix.
Tap for more steps...
Step 8.2.3.2.1
Cancel the common factor of .
Tap for more steps...
Step 8.2.3.2.1.1
Factor out of .
Step 8.2.3.2.1.2
Cancel the common factor.
Step 8.2.3.2.1.3
Rewrite the expression.
Step 8.2.3.2.2
Multiply .
Tap for more steps...
Step 8.2.3.2.2.1
Combine and .
Step 8.2.3.2.2.2
Multiply by .
Step 8.2.3.2.3
Cancel the common factor of .
Tap for more steps...
Step 8.2.3.2.3.1
Factor out of .
Step 8.2.3.2.3.2
Cancel the common factor.
Step 8.2.3.2.3.3
Rewrite the expression.
Step 8.3
To write as a fraction with a common denominator, multiply by .
Step 8.4
Simplify terms.
Tap for more steps...
Step 8.4.1
Combine and .
Step 8.4.2
Combine the numerators over the common denominator.
Step 8.5
Simplify the numerator.
Tap for more steps...
Step 8.5.1
Move to the left of .
Step 8.5.2
Multiply by each element of the matrix.
Step 8.5.3
Simplify each element in the matrix.
Tap for more steps...
Step 8.5.3.1
Apply the distributive property.
Step 8.5.3.2
Multiply .
Tap for more steps...
Step 8.5.3.2.1
Multiply by .
Step 8.5.3.2.2
Combine and .
Step 8.5.3.3
Move the negative in front of the fraction.
Step 8.5.3.4
Cancel the common factor of .
Tap for more steps...
Step 8.5.3.4.1
Cancel the common factor.
Step 8.5.3.4.2
Rewrite the expression.
Step 8.5.3.5
Multiply .
Tap for more steps...
Step 8.5.3.5.1
Combine and .
Step 8.5.3.5.2
Multiply by .
Step 8.5.4
Simplify each term.
Tap for more steps...
Step 8.5.4.1
To write as a fraction with a common denominator, multiply by .
Step 8.5.4.2
Combine and .
Step 8.5.4.3
Combine the numerators over the common denominator.
Step 8.5.4.4
Simplify the numerator.
Tap for more steps...
Step 8.5.4.4.1
Factor out of .
Tap for more steps...
Step 8.5.4.4.1.1
Factor out of .
Step 8.5.4.4.1.2
Factor out of .
Step 8.5.4.4.1.3
Factor out of .
Step 8.5.4.4.2
Move to the left of .
Step 8.6
Reorder factors in .