Question

6a2 - 8a - 30

Answer 1

look at the first coefficient 6 and last one-30
we need to find factors of both 6 and 30
6: 1,2,3,6
30: 1,2,3,5,6,10,15,30

now we want the factorize to become like this
( ) ( )
also we want the factors of 6 to times and plus the factors of 30 to get -8a, I will show you what I mean.
You have to experiment with the factors to find which one works, after two trials I found that this works.
(6a + 10)(a-3)=0
to test if it works, expand it using the crab claw/Foil method and u will get the same equation as listed above.

6a + 10 = 0 a-3 = 0
6a = -10 a = 3
a = -10/6

Answer 2

First step is to find out what the question is.
If it involves factoring, then first factor a 2 out of every term.
2(3a^2 - 4a - 15)
Now multiply 3 and -15 to get -45
We need two factors of -45 that add up to -4: -9 and 5
Now break up the middle term into -9a and 4a
2(3a^2 -9x + 5a - 15)
Now factor by parts
2[3a(a - 3) + 5(a - 3)]
Now factor out (a - 3)
2(a-3)(3a + 5)