Precalculus Examples

Solve by Substitution x^2-4y=19 , x^2+y^2=16
,
Step 1
Solve for in .
Tap for more steps...
Step 1.1
Subtract from both sides of the equation.
Step 1.2
Divide each term in by and simplify.
Tap for more steps...
Step 1.2.1
Divide each term in by .
Step 1.2.2
Simplify the left side.
Tap for more steps...
Step 1.2.2.1
Cancel the common factor of .
Tap for more steps...
Step 1.2.2.1.1
Cancel the common factor.
Step 1.2.2.1.2
Divide by .
Step 1.2.3
Simplify the right side.
Tap for more steps...
Step 1.2.3.1
Simplify each term.
Tap for more steps...
Step 1.2.3.1.1
Move the negative in front of the fraction.
Step 1.2.3.1.2
Dividing two negative values results in a positive value.
Step 2
Replace all occurrences of with in each equation.
Tap for more steps...
Step 2.1
Replace all occurrences of in with .
Step 2.2
Simplify the left side.
Tap for more steps...
Step 2.2.1
Simplify .
Tap for more steps...
Step 2.2.1.1
Simplify each term.
Tap for more steps...
Step 2.2.1.1.1
Rewrite as .
Step 2.2.1.1.2
Expand using the FOIL Method.
Tap for more steps...
Step 2.2.1.1.2.1
Apply the distributive property.
Step 2.2.1.1.2.2
Apply the distributive property.
Step 2.2.1.1.2.3
Apply the distributive property.
Step 2.2.1.1.3
Simplify and combine like terms.
Tap for more steps...
Step 2.2.1.1.3.1
Simplify each term.
Tap for more steps...
Step 2.2.1.1.3.1.1
Multiply .
Tap for more steps...
Step 2.2.1.1.3.1.1.1
Multiply by .
Step 2.2.1.1.3.1.1.2
Multiply by .
Step 2.2.1.1.3.1.1.3
Multiply by .
Step 2.2.1.1.3.1.1.4
Multiply by .
Step 2.2.1.1.3.1.1.5
Multiply by .
Step 2.2.1.1.3.1.2
Multiply .
Tap for more steps...
Step 2.2.1.1.3.1.2.1
Multiply by .
Step 2.2.1.1.3.1.2.2
Multiply by .
Step 2.2.1.1.3.1.3
Move to the left of .
Step 2.2.1.1.3.1.4
Multiply .
Tap for more steps...
Step 2.2.1.1.3.1.4.1
Multiply by .
Step 2.2.1.1.3.1.4.2
Multiply by .
Step 2.2.1.1.3.1.5
Move to the left of .
Step 2.2.1.1.3.1.6
Combine.
Step 2.2.1.1.3.1.7
Multiply by by adding the exponents.
Tap for more steps...
Step 2.2.1.1.3.1.7.1
Use the power rule to combine exponents.
Step 2.2.1.1.3.1.7.2
Add and .
Step 2.2.1.1.3.1.8
Multiply by .
Step 2.2.1.1.3.2
Subtract from .
Step 2.2.1.1.4
Simplify each term.
Tap for more steps...
Step 2.2.1.1.4.1
Cancel the common factor of .
Tap for more steps...
Step 2.2.1.1.4.1.1
Factor out of .
Step 2.2.1.1.4.1.2
Factor out of .
Step 2.2.1.1.4.1.3
Cancel the common factor.
Step 2.2.1.1.4.1.4
Rewrite the expression.
Step 2.2.1.1.4.2
Rewrite as .
Step 2.2.1.2
To write as a fraction with a common denominator, multiply by .
Step 2.2.1.3
Combine and .
Step 2.2.1.4
Combine the numerators over the common denominator.
Step 2.2.1.5
Subtract from .
Tap for more steps...
Step 2.2.1.5.1
Reorder and .
Step 2.2.1.5.2
Subtract from .
Step 2.2.1.6
Move the negative in front of the fraction.
Step 3
Solve for in .
Tap for more steps...
Step 3.1
Substitute into the equation. This will make the quadratic formula easy to use.
Step 3.2
Multiply each term in by to eliminate the fractions.
Tap for more steps...
Step 3.2.1
Multiply each term in by .
Step 3.2.2
Simplify the left side.
Tap for more steps...
Step 3.2.2.1
Simplify each term.
Tap for more steps...
Step 3.2.2.1.1
Cancel the common factor of .
Tap for more steps...
Step 3.2.2.1.1.1
Cancel the common factor.
Step 3.2.2.1.1.2
Rewrite the expression.
Step 3.2.2.1.2
Cancel the common factor of .
Tap for more steps...
Step 3.2.2.1.2.1
Move the leading negative in into the numerator.
Step 3.2.2.1.2.2
Factor out of .
Step 3.2.2.1.2.3
Cancel the common factor.
Step 3.2.2.1.2.4
Rewrite the expression.
Step 3.2.2.1.3
Multiply by .
Step 3.2.2.1.4
Cancel the common factor of .
Tap for more steps...
Step 3.2.2.1.4.1
Cancel the common factor.
Step 3.2.2.1.4.2
Rewrite the expression.
Step 3.2.3
Simplify the right side.
Tap for more steps...
Step 3.2.3.1
Multiply by .
Step 3.3
Subtract from both sides of the equation.
Step 3.4
Subtract from .
Step 3.5
Factor using the AC method.
Tap for more steps...
Step 3.5.1
Consider the form . Find a pair of integers whose product is and whose sum is . In this case, whose product is and whose sum is .
Step 3.5.2
Write the factored form using these integers.
Step 3.6
If any individual factor on the left side of the equation is equal to , the entire expression will be equal to .
Step 3.7
Set equal to and solve for .
Tap for more steps...
Step 3.7.1
Set equal to .
Step 3.7.2
Add to both sides of the equation.
Step 3.8
Set equal to and solve for .
Tap for more steps...
Step 3.8.1
Set equal to .
Step 3.8.2
Add to both sides of the equation.
Step 3.9
The final solution is all the values that make true.
Step 3.10
Substitute the real value of back into the solved equation.
Step 3.11
Solve the first equation for .
Step 3.12
Solve the equation for .
Tap for more steps...
Step 3.12.1
Take the specified root of both sides of the equation to eliminate the exponent on the left side.
Step 3.12.2
The complete solution is the result of both the positive and negative portions of the solution.
Tap for more steps...
Step 3.12.2.1
First, use the positive value of the to find the first solution.
Step 3.12.2.2
Next, use the negative value of the to find the second solution.
Step 3.12.2.3
The complete solution is the result of both the positive and negative portions of the solution.
Step 3.13
Solve the second equation for .
Step 3.14
Solve the equation for .
Tap for more steps...
Step 3.14.1
Remove parentheses.
Step 3.14.2
Take the specified root of both sides of the equation to eliminate the exponent on the left side.
Step 3.14.3
The complete solution is the result of both the positive and negative portions of the solution.
Tap for more steps...
Step 3.14.3.1
First, use the positive value of the to find the first solution.
Step 3.14.3.2
Next, use the negative value of the to find the second solution.
Step 3.14.3.3
The complete solution is the result of both the positive and negative portions of the solution.
Step 3.15
The solution to is .
Step 4
Replace all occurrences of with in each equation.
Tap for more steps...
Step 4.1
Replace all occurrences of in with .
Step 4.2
Simplify the right side.
Tap for more steps...
Step 4.2.1
Simplify .
Tap for more steps...
Step 4.2.1.1
Combine the numerators over the common denominator.
Step 4.2.1.2
Rewrite as .
Tap for more steps...
Step 4.2.1.2.1
Use to rewrite as .
Step 4.2.1.2.2
Apply the power rule and multiply exponents, .
Step 4.2.1.2.3
Combine and .
Step 4.2.1.2.4
Cancel the common factor of .
Tap for more steps...
Step 4.2.1.2.4.1
Cancel the common factor.
Step 4.2.1.2.4.2
Rewrite the expression.
Step 4.2.1.2.5
Evaluate the exponent.
Step 4.2.1.3
Simplify the expression.
Tap for more steps...
Step 4.2.1.3.1
Add and .
Step 4.2.1.3.2
Divide by .
Step 5
Replace all occurrences of with in each equation.
Tap for more steps...
Step 5.1
Replace all occurrences of in with .
Step 5.2
Simplify the right side.
Tap for more steps...
Step 5.2.1
Simplify .
Tap for more steps...
Step 5.2.1.1
Combine the numerators over the common denominator.
Step 5.2.1.2
Simplify each term.
Tap for more steps...
Step 5.2.1.2.1
Apply the product rule to .
Step 5.2.1.2.2
Raise to the power of .
Step 5.2.1.2.3
Multiply by .
Step 5.2.1.2.4
Rewrite as .
Tap for more steps...
Step 5.2.1.2.4.1
Use to rewrite as .
Step 5.2.1.2.4.2
Apply the power rule and multiply exponents, .
Step 5.2.1.2.4.3
Combine and .
Step 5.2.1.2.4.4
Cancel the common factor of .
Tap for more steps...
Step 5.2.1.2.4.4.1
Cancel the common factor.
Step 5.2.1.2.4.4.2
Rewrite the expression.
Step 5.2.1.2.4.5
Evaluate the exponent.
Step 5.2.1.3
Simplify the expression.
Tap for more steps...
Step 5.2.1.3.1
Add and .
Step 5.2.1.3.2
Divide by .
Step 6
Replace all occurrences of with in each equation.
Tap for more steps...
Step 6.1
Replace all occurrences of in with .
Step 6.2
Simplify the right side.
Tap for more steps...
Step 6.2.1
Simplify .
Tap for more steps...
Step 6.2.1.1
Combine the numerators over the common denominator.
Step 6.2.1.2
Rewrite as .
Tap for more steps...
Step 6.2.1.2.1
Use to rewrite as .
Step 6.2.1.2.2
Apply the power rule and multiply exponents, .
Step 6.2.1.2.3
Combine and .
Step 6.2.1.2.4
Cancel the common factor of .
Tap for more steps...
Step 6.2.1.2.4.1
Cancel the common factor.
Step 6.2.1.2.4.2
Rewrite the expression.
Step 6.2.1.2.5
Evaluate the exponent.
Step 6.2.1.3
Simplify the expression.
Tap for more steps...
Step 6.2.1.3.1
Add and .
Step 6.2.1.3.2
Divide by .
Step 7
Replace all occurrences of with in each equation.
Tap for more steps...
Step 7.1
Replace all occurrences of in with .
Step 7.2
Simplify the right side.
Tap for more steps...
Step 7.2.1
Simplify .
Tap for more steps...
Step 7.2.1.1
Combine the numerators over the common denominator.
Step 7.2.1.2
Simplify each term.
Tap for more steps...
Step 7.2.1.2.1
Apply the product rule to .
Step 7.2.1.2.2
Raise to the power of .
Step 7.2.1.2.3
Multiply by .
Step 7.2.1.2.4
Rewrite as .
Tap for more steps...
Step 7.2.1.2.4.1
Use to rewrite as .
Step 7.2.1.2.4.2
Apply the power rule and multiply exponents, .
Step 7.2.1.2.4.3
Combine and .
Step 7.2.1.2.4.4
Cancel the common factor of .
Tap for more steps...
Step 7.2.1.2.4.4.1
Cancel the common factor.
Step 7.2.1.2.4.4.2
Rewrite the expression.
Step 7.2.1.2.4.5
Evaluate the exponent.
Step 7.2.1.3
Simplify the expression.
Tap for more steps...
Step 7.2.1.3.1
Add and .
Step 7.2.1.3.2
Divide by .
Step 8
Replace all occurrences of with in each equation.
Tap for more steps...
Step 8.1
Replace all occurrences of in with .
Step 8.2
Simplify the right side.
Tap for more steps...
Step 8.2.1
Simplify .
Tap for more steps...
Step 8.2.1.1
Combine the numerators over the common denominator.
Step 8.2.1.2
Rewrite as .
Tap for more steps...
Step 8.2.1.2.1
Use to rewrite as .
Step 8.2.1.2.2
Apply the power rule and multiply exponents, .
Step 8.2.1.2.3
Combine and .
Step 8.2.1.2.4
Cancel the common factor of .
Tap for more steps...
Step 8.2.1.2.4.1
Cancel the common factor.
Step 8.2.1.2.4.2
Rewrite the expression.
Step 8.2.1.2.5
Evaluate the exponent.
Step 8.2.1.3
Simplify the expression.
Tap for more steps...
Step 8.2.1.3.1
Add and .
Step 8.2.1.3.2
Divide by .
Step 9
Replace all occurrences of with in each equation.
Tap for more steps...
Step 9.1
Replace all occurrences of in with .
Step 9.2
Simplify the right side.
Tap for more steps...
Step 9.2.1
Simplify .
Tap for more steps...
Step 9.2.1.1
Combine the numerators over the common denominator.
Step 9.2.1.2
Rewrite as .
Tap for more steps...
Step 9.2.1.2.1
Use to rewrite as .
Step 9.2.1.2.2
Apply the power rule and multiply exponents, .
Step 9.2.1.2.3
Combine and .
Step 9.2.1.2.4
Cancel the common factor of .
Tap for more steps...
Step 9.2.1.2.4.1
Cancel the common factor.
Step 9.2.1.2.4.2
Rewrite the expression.
Step 9.2.1.2.5
Evaluate the exponent.
Step 9.2.1.3
Simplify the expression.
Tap for more steps...
Step 9.2.1.3.1
Add and .
Step 9.2.1.3.2
Divide by .
Step 10
Replace all occurrences of with in each equation.
Tap for more steps...
Step 10.1
Replace all occurrences of in with .
Step 10.2
Simplify the right side.
Tap for more steps...
Step 10.2.1
Simplify .
Tap for more steps...
Step 10.2.1.1
Combine the numerators over the common denominator.
Step 10.2.1.2
Simplify each term.
Tap for more steps...
Step 10.2.1.2.1
Apply the product rule to .
Step 10.2.1.2.2
Raise to the power of .
Step 10.2.1.2.3
Multiply by .
Step 10.2.1.2.4
Rewrite as .
Tap for more steps...
Step 10.2.1.2.4.1
Use to rewrite as .
Step 10.2.1.2.4.2
Apply the power rule and multiply exponents, .
Step 10.2.1.2.4.3
Combine and .
Step 10.2.1.2.4.4
Cancel the common factor of .
Tap for more steps...
Step 10.2.1.2.4.4.1
Cancel the common factor.
Step 10.2.1.2.4.4.2
Rewrite the expression.
Step 10.2.1.2.4.5
Evaluate the exponent.
Step 10.2.1.3
Simplify the expression.
Tap for more steps...
Step 10.2.1.3.1
Add and .
Step 10.2.1.3.2
Divide by .
Step 11
Replace all occurrences of with in each equation.
Tap for more steps...
Step 11.1
Replace all occurrences of in with .
Step 11.2
Simplify the right side.
Tap for more steps...
Step 11.2.1
Simplify .
Tap for more steps...
Step 11.2.1.1
Combine the numerators over the common denominator.
Step 11.2.1.2
Rewrite as .
Tap for more steps...
Step 11.2.1.2.1
Use to rewrite as .
Step 11.2.1.2.2
Apply the power rule and multiply exponents, .
Step 11.2.1.2.3
Combine and .
Step 11.2.1.2.4
Cancel the common factor of .
Tap for more steps...
Step 11.2.1.2.4.1
Cancel the common factor.
Step 11.2.1.2.4.2
Rewrite the expression.
Step 11.2.1.2.5
Evaluate the exponent.
Step 11.2.1.3
Simplify the expression.
Tap for more steps...
Step 11.2.1.3.1
Add and .
Step 11.2.1.3.2
Divide by .
Step 12
Replace all occurrences of with in each equation.
Tap for more steps...
Step 12.1
Replace all occurrences of in with .
Step 12.2
Simplify the right side.
Tap for more steps...
Step 12.2.1
Simplify .
Tap for more steps...
Step 12.2.1.1
Combine the numerators over the common denominator.
Step 12.2.1.2
Simplify each term.
Tap for more steps...
Step 12.2.1.2.1
Apply the product rule to .
Step 12.2.1.2.2
Raise to the power of .
Step 12.2.1.2.3
Multiply by .
Step 12.2.1.2.4
Rewrite as .
Tap for more steps...
Step 12.2.1.2.4.1
Use to rewrite as .
Step 12.2.1.2.4.2
Apply the power rule and multiply exponents, .
Step 12.2.1.2.4.3
Combine and .
Step 12.2.1.2.4.4
Cancel the common factor of .
Tap for more steps...
Step 12.2.1.2.4.4.1
Cancel the common factor.
Step 12.2.1.2.4.4.2
Rewrite the expression.
Step 12.2.1.2.4.5
Evaluate the exponent.
Step 12.2.1.3
Simplify the expression.
Tap for more steps...
Step 12.2.1.3.1
Add and .
Step 12.2.1.3.2
Divide by .
Step 13
The solution to the system is the complete set of ordered pairs that are valid solutions.
Step 14
The result can be shown in multiple forms.
Point Form:
Equation Form:
Step 15