Answer:
[tex](2a+7)(3b-4)[/tex]
Step-by-step explanation:
The given expression is
[tex]6ab-8a+21b-28[/tex]
Make the groups for this expression as shown below
[tex](6ab-8a)+(21b-28)[/tex]
Factor out GCF from each group
[tex]2a(3b-4)+7(3b-4)[/tex]
Now, (3b-4) is common. Hence, factored out this, we get
[tex](3b-4)(2a+7)[/tex]
Therefore, the factored form of the given expression is
[tex](2a+7)(3b-4)[/tex]
Third option is correct.
