Respuesta :
I would say the answer is 8:
f(x) = 2x^2 + 8
f(x) = 136
f(x) = f(x)
2x^2 + 8 = 136
Subtract both sides by 8
2x^2=128
Divide both sides by 2
x^2 = 64
Square both sides
x = 8
f(x) = 2x^2 + 8
f(x) = 136
f(x) = f(x)
2x^2 + 8 = 136
Subtract both sides by 8
2x^2=128
Divide both sides by 2
x^2 = 64
Square both sides
x = 8