To solve this question, we can do it both ways. we can get rid of the 7 by dividing it, or we can distribute it to the parenthesis. let's do this the distribution way.
63=7(5+7b)
When distributing, the number behind (7) goes to both and all terms in the parenthesis.
63=7(5)+7(7b)
Multiply.
63=35+49b
Subtract 35.
28=47b
Divide by 49.
0.57=b
