How do I solve the system by the method of substitution?

Question

Solve {-x-y=-7, x^2-y=-5

Answer 1

if

-x-y = -7 and x2-y = -5 Let's substitute y from the first equation into the second equation

x2 - (-x + 7) = -5 which simplifies to x2 + x -2 = 0 we get 2 roots from a quadratic equation, they are

x = 1 and -2

Substituting the roots into equation 1: -1-y = -7 implies that y = 6

or -(-2) - y = -7 implies y = 9

Do they satisfy both equations? Check! You will find that (1,6) and (-2,9) satisfy the two equations!