y = -x^2 4

y = 2x 1

Subtract the bottom equation from the top .

Hence

0 = -x^2 2x 3

x^2 2x 3 = 0

Factor

( x 3)(x 1) = 0

x = -3

y = -x^2 4

y = 2x 1

Subtract the bottom equation from the top .

Hence

0 = -x^2 2x 3

x^2 2x 3 = 0

Factor

( x 3)(x 1) = 0

x = -3