How do you solve the system by the method of substitution? x^2-y^2=9 x-y=1

Expert Answers

An illustration of the letter 'A' in a speech bubbles

We have to solve the following system of equations by substitution.

  • x^2 - y^2 = 9
  • x - y = 1

x - y = 1

=> x = 1 + y

Substitute this for x in x^2 - y^2 = 9

=> (1 + y)^2 - y^2 = 9

...

Unlock
This Answer Now

Start your 48-hour free trial to unlock this answer and thousands more. Enjoy eNotes ad-free and cancel anytime.

Start your 48-Hour Free Trial

We have to solve the following system of equations by substitution.

  • x^2 - y^2 = 9
  • x - y = 1

x - y = 1

=> x = 1 + y

Substitute this for x in x^2 - y^2 = 9

=> (1 + y)^2 - y^2 = 9

=> 1 + y^2 + 2y - y^2 = 9

=> 1 + 2y = 9

=> 2y = 8

=> y = 4

x = 1 + y

=> 1 + 4

=> 5

We get x = 5 and y = 4

Approved by eNotes Editorial Team