Answer:
r(b) = 4b +3
Step-by-step explanation:
There are only two variables and the one that is not b is r. So, this amounts to solving for r. Divide the given equation by the coefficient of r:
... 4b = r -3
Add the constant:
... 4b +3 = r
Express in function notation.
... r(b) = 4b +3