An artificial lake is in the shape of a rectangle and has an area of 9/20 square mile. the width of the lake is 1/5 the length of the lake. what are the dimensions of the lake?

Area= length * width

plug in the numbers known

9/20= L * 1/5

divide both sides by 1/5
9/20 ÷ 1/5= L

multiply by the 1/5 reciprocal/inverse
9/20 * 5/1= L

(9*5)/(20*1)= L
45/20= L

simply top & bottom by 5
9/4= L

change to mixed number
2 1/4= L

The length is 2 1/4 miles.

Hope this helps! :)