Question

Completely factor the expression
20x^2-45y^2

Answer 1

5(4x^2-9y^2) = 5((2x+3y)(2x-3y))

Answer 2

Parentheses are important

Answer 3

k

Answer 4

Because the entire expression is being multiplied by 5. This had me for a minute, but I remembered that I saw this kind of problem before and the first step is to factor out what is common to both terms. 5 is the only thing common to both terms so factor that out first.