Answer :

7b - 2b + 3 - 1 = 0

(7b - 2b) = 5b
3 - 1 = 2

Thus:

5b + 2 = 0
5b = -2
b = -2/5 = -0.4
7b-2b+3-1=0
5b+2=0
5b=-2
b=-2/5