Question

Factor the expression: x^2+9x+20 , and show work so I understand how to do it pleasee?

Answer 1

(x+5)(x+4)

Answer 2

do you recall something called "foil"?

Answer 3

find first the possible factors of 20,. and then check if their sum is 9.. then,. x^2 can be written as the square of x

Answer 4

Oh, thank you! but no I dont recall foil , what is is?

Answer 5

is it*

Answer 6

its a memory device taught to children to help them remember how to multiply binomials ...

Answer 7

if you know how to multiply: (x+a)(x+b)

then you can use that to compare parts with to understand the product/sum concept

Answer 8

Oh, I think I kinda remember that

Answer 9

"foil" is a process of multiplying binomial terms,,. f means first term to first term, o means outer term,. i means inner term and l means last term to last term..

Answer 10

\[(x+a)(x+b)\]
\[\large x^2 + \underbrace{ax+bx}_{(a+b)x}+ab\]

Answer 11

so in order to factor it back into (x+a)(x+b)

you would find the factors of the last term, that add up to the middle coefficient

Answer 12

Ohh, alright thank you!! I understand that now