Question

Identify which equation is a quadratic equation.

y = −6x − 3

y + x2 = (x − 1)(x + 7)

y − 9 = (x − 1)(x2 + 4)

y = 5x(x + 3) − 8

Answer 1

Simplify them and check.

Answer 2

then what?

Answer 3

Then you'll know. All you have to do is simplify each equation and you'll know whether they're a quadratic or not.