Question

Identify which equation is a quadratic equation.

y = 3x + 4

y + x2 = (x − 2)(x + 7)

y = −4x(x − 4) + 2x

y + 3 = (x + 12)(x2 + 2)

Answer 1

all except 1st

Answer 2

Remember that quadratic equations are of the form \[y=ax^2+bx+c\], so arrange each equation into that form (if possible). If it's not possible, then the equation in question is not a quadratic equation.

Answer 3

second is NOT a quadratic equation because the x^2 on the left side and the x^2 on the right side will cancel out (through subtraction)