Question

On a recent math test, a student wrote that (x + 4)^2 = (x^2 + 16). Are they correct? Provide reasons for your answer

Answer 1

No

(x + 4) ^2 = (x^2 + 8x + 16)

Explanation:

You have to factor the equation (X + 4) ^2.

Expanded: (x + 4) * (x + 4)

Using the foil technique:

First: (x) * (x) = x^2

Outer: (x) * (4) = 4x

Inner: (4) * (x) = 4x

Last: (4) * (4) = 16

Factor equations should look like this

a^2 + bx + c, where the Outer and Inner values are added together. Resulting in:

x^2 + 8x + 16