I ussually dont need help for the types of question, but I am having alot of diffuculty isolating r by itself on one side of the = sign.

Assume a person invests $210 at the end of each year for 10 years at an annual interest rate of r. The ammount of money, A, in the account after 10 years is

A = $\displaystyle \frac{210((1+r)^{10}-1)}{r}$

his goal is to have 3089 in his account after 10 years.

$\displaystyle \frac{210((1+r)^{10}-1)}{r}= 3089$