Question

Which expressions represent a difference in squares?

Select each correct answer:
a. k^2+81
b. t^2-4
c. 9x^2-100
d. 8x^2-20
e. 4a^2-36

Answer 1

We have minus signs in between b. t^2-4, c. 9x^2-100, d. 8x^2-20 and e. 4a^2-36.

But we can see..

t^2-4 has perfect square 4.

9x^2-100 has perfect squares 9 and 100.

8x^2-20 don't have perfect squares 8 and 20.

4a^2-36 has perfect squares 2 and 6.

Therefore, b. t^2-4, c. 9x^2-100 and e. 4a^2-36 expressions represent a difference in squares.