2(b + 3) - (7 + b) = -7
2b + 6 - 7 - b = -7
b = -6 + 7 - 7
b = -6
To solve this first distribute the 2, and then distribute the negative sign.
2(b+3)-(7+b)=-7
2b+6-7-b=-7
Combine like terms.
2b+(-b)=b
6+(-7)=-1
b-1=-7
Add 1 on both sides of the equation.
b-1+1=-7+1
b=-6
