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
