Question

How to factor by grouping

Answer 1

Step1: group the first two terms together 
next step 2:factor out a GFC from each separate binomical
next step 3: factor out the common binomial

Answer 2

Put parenthesis:
(2x+16)+(xy+8y)

Find the greatest common factor in between the two terms in each parenthesis:
2(x+8)+y(x+8)

Since the thing in the parenthesis are now the same, you can change their order:
(y+2)(x+8)

The answer is (x+8)(y+2)

Hope this helped!