How to factor by grouping: 4g^2 + 12gh + 5g + 15h
This is what I have so far:

4g^2 + 12gh and 5g + 15h
gcf: 4g and 5

Distribute backwards:
4g(? + ?)4g^2 + 12gh and 5(? + ?)5g + 15h
(g + 3h) (g + 3h)

I know the gcf is g and 3h, but I'm not sure what step to take from here.

Question

How to factor by grouping: 4g^2 + 12gh + 5g + 15h
This is what I have so far:

4g^2 + 12gh and 5g + 15h
gcf: 4g and 5

Distribute backwards:
4g(? + ?)4g^2 + 12gh and 5(? + ?)5g + 15h
   (g + 3h)                             (g + 3h)
 
I know the gcf is g and 3h, but I'm not sure what step to take from here.

jim_thompson5910 · Answer

4g^2 + 12gh + 5g + 15h

(4g^2 + 12gh) + (5g + 15h)

4g(g + 3h) + (5g + 15h)

4g(g + 3h) + 5(g + 3h) <<<- You managed to get here, so nice work

(4g + 5)(g + 3h)