Answer:
The equation with "b" as the independent variable is "a = 3*b + 13".
Explanation:
The dependent variable is the one that is a function of the value of the independent one. That means that usually the dependent variable is isolated in the left side of the equation, while the indepedent one is on the right side of the equation, therefore to make "b" the independent variable we must isolate "a" on the left side. We have:
a -7 = 3*(b + 2)
a = 3*(b + 2) + 7
a = 3*b + 6 + 7
a = 3*b + 13