my post is still on this page as algebra, could someone elaborate on what bobpursley tried to help me with.

Question

See your original post.

I am guessing you are referring to your question

5)Simplify:(5x-4)^2

and your answer= 25x^2 - 16

(5x-4)^2
=(5x-4)(5x-4)
= 25x^2 - 20x - 20x + 16
= 25x^2 - 40x + 16

The FOIL that bobpurseley was referring to means
F - multiply the firsts
O - multiply the outside terms
I - multiply the inside terms
L - multiply multiply the last terms

it is a short memory-aid to help you multiply two binomials

Answer 1

Multiply 3/7 times 9/10