Quadratic function? (factoring)

I did it, but when I plug it in to check it it doesn't equal? Keep getting one negative and one positive? What did i do wrong?

x^2=-11x-10 (factoring method)

I got x=-10 or -1

You did it right.

When you plug it in, they are in fact equal:

(-10)^2 = -11(-10) - 10
100 = 110 - 10
100 = 100

(-1)^2 = -11(-1) - 10
1 = 11 - 10
1 = 1

x^2 = -11x - 10

x^2 + 11x + 10 = 0

(x+10)(x+1) = 0

x = -1
x = -10

(-1)^2 = -11 (-1) - 10

1 = 11 - 10 = 1 check

(-10)^2 = -11(-10) - 10

100 = 110 - 10 = 100 check.

You did it right