Question

Identify the factors of 6ab − 8a + 21b − 28. (5 points)

(2a + 4)(3b − 7)
(2a − 4)(3b + 7)
(2a + 7)(3b − 4)
(2a − 7)(3b + 4)

Answer 1

rearrange to

6ab+21b-8a-28 now factor 1st and 2nd pair of terms...

3b(2a+7)-4(2a+7)

(3b-4)(2a+7)

So it is the third one down...

Answer 2

`(2a+7)(3b-4)`

Explanation:

The given expression is

`6ab-8a+21b-28`

Make the groups for this expression as shown below

`(6ab-8a)+(21b-28)`

Factor out GCF from each group

`2a(3b-4)+7(3b-4)`

Now, (3b-4) is common. Hence, factored out this, we get

`(3b-4)(2a+7)`

Therefore, the factored form of the given expression is

`(2a+7)(3b-4)`

Third option is correct.