## HelloKitty17 one year ago Factor completely 10x2 + 2x – 8. 2(5x - 1)(x + 4) 2(5x - 4)(x + 1) 2(5x + 2)(x - 2) 2(5x - 2)(x + 2)

1. freckles

do you know the greatest common factor of 10,2,8?

2. HelloKitty17

2

3. freckles

great so when you factor out 2 you have $10x^2+2x-8 \\ 2(5)x^2+2(1)x-2(4) \\ 2(5x^2+1x-4)$ now let's look at factoring the thingy in ( ) That is let's look at factoring: $5x^2+1x-4 \text{ aka } 5x^2+x-4$

4. freckles

notice a=5 b=1 c=-4 you are looking for two factors of ac that have product ac and sum b

5. freckles

that is what two integer numbers when you multiply them give you -20 and when you add them give you 1

6. OregonDuck

2*(x+1)*(5x-4)

7. OregonDuck

so b

8. freckles

Remember to not give direct answers in the future. Thank you kindly.

9. OregonDuck

ok sorry