PLEASE SHOW FORMULAS/ HOW TO WORK IT OUT

A share of common stock has just paid a dividend of $2.00. If the expected long-run growth rate for this stock is 7%, and if investors require a(n) 11% rate of return, what is the price of the stock? $53.50

The Tapley Tank Company's last dividend was $2.00. The dividend growth rate is expected to be constant at 25% for 3 years, after which dividends are expected to grow at a rate of 7% forever. Tapley's required return (r_s) is 11%. What is Tapley's current stock price? $84.05