Question

Which of the following equations is quadratic?

A.) x(x^2 + 1) = 0

B.)5(4x + 2) = 3

C.) (x + 3)(x + 4) = 5

Answer 1

First, why not write out the usual equation of a quadratic function, beginning with the x^2 power, followed by the x and then a constant?

then compare each of the given answer choices to this standard form. You may have to multiply out the terms of the possible answers to make the comparison easier.