Solve. 2b + 4 + 5b + 7 = - 10
a. -3
b. - 1/7
c. 1/7
d. 3

It's A, just as I said before,
7b + 11 =-10
7b = -21
b = -21/7
b = -3

To solve this equation, you have to substract b with b and numbers with numbers first :

2b + 4 + 5b + 7 = - 10
7b + 11 =-10

Afterwards, you combine letters at the left and the numbers at the right :

7b = -21

Now instead of getting 7b, we want to obtain just b, therefore we divide by 7 in each member. 

b = -21/7
b = -3.

Therefore, the answer is A. -3.

Hope this helps !

Photon