(2h+7)(2h-7)

Question

How you get the answers?

Answer 1

First, you open one set of parentheses, enabling you to multiply each term by the other expression in parentheses:

2h(2h-7)+7(2h-7).

Now you open the other parentheses and multiply by what's outside;

2h*2h-2h*7+7*2h-7*7= 4h^2-14h+14h-49= 4h^2-49 because the middle terms cancel out.