Question

1. Which binomial is a difference of squares?
(Points : 1)
14x2 – 81

16x3 – 81

25x2 + 81

36x2 – 81

Answer 1

What is a difference? That rules out one of the answers right away. What's a square? Well that is when you raise something to the second power. That automatically gets rid of another one.

Now are the numbers themselves squares? Factor them into their prime factors and you should see that they are made up of two numbers multiplied together! Keep in mind that:

2*2*2*2=4*4 so just because 16 is also 2^4 it's also 4^2.