Question

Which equation is a quadratic equation?
a)y + 7 = −3x(4 − x) + 9x
b)y = −2x + 5
c)y + 2x3 = (2x − 2)(x + 5)
d) y − 9x = (x2 + 1)(5x − 1) + 3

Answer 1

then written in standard form only A is the quadratic in x