Question

Factor -x^2+3x+40

Answer 1

yes

Answer 2

so what adds up to 3 that when multiplied equals 40?

Answer 3

the factors can be negative

Answer 4

2?

Answer 5

think of factors of 40

Answer 6

so, 2,4,5, 8, 10, 20, and so on

Answer 7

so where do you see a gap of 3 in the factors I just showed you?

Answer 8

I don't get it at all.

Answer 9

so the numbers I typed were factors of 40, right?

Answer 10

yeah

Answer 11

how many numbers are from 5-8? 3, right?

Answer 12

5-6, 6-7, and 7-8, so 3.

Answer 13

once you know the two factors, it's easy. All you have to do is plug it in.

Answer 14

so(-x+___)(x+___)

Answer 15

so just insert and if you need to check, just FOIL

Answer 16

therefore the answer is (-x +8)(x+5)

Answer 17

-x^2+8x-5x+40
-x(x-8)-5(x-8)
(-x-5)(x-8)
-(x+5)(x-8)

Answer 18

you could do it that way too.

Answer 19

got it em ???

Answer 20

thankyou

Answer 21

np =) its all about finding the right factors then plugging them in