Question

(2r+5f)(2r-5f)

Answer 1

What is the problem with this?

Answer 2

I think i was foiling it out wrong.

Answer 3

what did you get?

Answer 4

multiply 2r together then 2r to the 2 5f's then 5f to negative 5f.
eveything cancels out leaving you with 2r^2-5f^2

Answer 5

i was combining them.

Answer 6

You can use this formula: \[(a+b)(a-b) = a^2-b^2\]

Answer 7

_ I had no idea but thank you !