Question

what mulitplies to -20 and adds up to -22

Answer 1

XY = -20
X + Y = -22

Answer 2

that's not what I meant.

Answer 3

Then what did you mean?

Answer 4

the factors of 20 that equals to 22

Answer 5

List all the factors of 20

20
1 and 20
2 and 10
4 and 5

so, there's none.

Answer 6

Oh right.

Answer 7

I realized that so I did something wrong

Answer 8

I don't know how to factor 12x2-22x-20

Answer 9

I see your mistake... that method only works when the a=1 in the ax^2

Factor out the common factor of 2 from everything first...

12x^2-22x-20 =

2(6x^2 - 11x - 10)

now you need to multiply the 6 and -10 to get -60

Now find factors of -60 that add up to -11

Answer 10

you're so smart.

Answer 11

Haha thank you :)

Answer 12

I forgot about that. The sub teacher is not good at math.

Answer 13

hehe yeah it's not often you get a sub who has a degree in math and physics :D

Answer 14

the sub does it really fast.

Answer 15

-6 + 1 does add up to -11.

Answer 16

actually you're suppose to multiply the 6 and the 10.

Answer 17

2(6x^2 - 11x - 10)

-60
-15 and 4
which add to -11

So break up the -11x into -15x and 4x:

2(6x^2 - 15x + 4x - 10)

Now try to factor by grouping

Answer 18

thanks Agent0smith i was stuck because i did not stop to factor i automatically was working
with the numbers that popped out

Answer 19

2(6x^2 - 15x + 4x - 10)
factor by grouping
2( 3x(2x - 5) + 2(2x - 5) )
then finally...
2(2x - 5)(3x + 2)

Answer 20

And I told you that.

Answer 21

told us what...?

Answer 22

I was trying to tell her your way she wasn't listening.