Question

Solve the system using any method
-x^2-10x-y=30
3x^2+30x-y=-66

Answer 1

(-4,-6) (-6,-6)

Explanation:

-y = x^2 + 10x + 30

y = -x^2 - 10x - 30

3x^2 + 30x -(-x^2-10x-30) = -66

3x^2 + 30x + x^2 + 10x + 30 = -66

4x^2 + 40x +30 + 66 = 0

4x^2 + 40x + 96 = 0

x^2 + 10x + 24 = 0

(x+6)(x+4) = 0

x = -6

x = -4

y = -x^2 - 10x - 30
y = -(-6)^2 - 10(-6) - 30

Y = -36+60 - 30

y= -6

y= -(-4)^2 - 10(-4) - 30

y = -16 + 40 - 30

y = -6