Question

Determine which polynomial is a difference of two squares. a. X2 + 14 b. X2 ? 14 c. X2 + 49 d. X2 ? 49

Answer 1

assuming the question marks are minus signs, the answer would be d. or x^2 - 49

Answer 2

d. X^2 - 49

Explanation:

I will assume that the question marks are minus signs.

Let's remember what does "difference of two squares" means:

The difference of two squares is a number multiplied by itself subtracted from another number multiplied by itself (the number multiplied by itself is called squared number).

In our options, the first number is always a squared number because it's X^2 = X * X.

We just have to analyze the second number.

First, let's notice that a. and c. can't be correct because we have a sum instead of a subtract.

We have left 14 and 49 to analyze:

14 = 7*2 (it's not a squared number)

49 = 7*7 (it's a squared number)

The answer is X*X - 7*7 = X^2 - 49