Please help, Find the perimeter of the figure to the nearest hundredth

For what value of (y) is 3^3/3^y =1/9

Last year, laura had $30,000 to invest. she invested some of it in an account that paid 7% simple interest per year, and she invested the rest in an account that paid 8% simple interest per year. after one year, she received a total of $2230 in interest. how much did she invest in each account?

Evaluate this exponential expression. (-27)^2/3 -9 9 81