Question

Which polynomial is a difference of two squares?

x2 + 25

x2 − 25

x2 − 10

x2 + 10

Answer 1

First, let's look at the equation to see if we can immediately eliminate any answers. They ask for the DIFFERENCE of two squares (subtraction), so we can immediately eliminate the first and the last answer.

Then they ask for two squares. Well, all of them contain x^2], which is definitely a square (x*x). So let's take the square root of the second term in our remaining choices (b and c).

If we take the square root of our second term in b, we are left with:
\[\sqrt{25}=5\] This could be an answer!

\[\sqrt{10}=3.16...\]This is not a square!

Therefore we can go with b.

Answer 2

thank you

Answer 3

You're very welcome :)