A rectangular plot 18 ft by 18 ft is to be used for a garden

A rectangular plot, 18 ft by 18 ft. is to be used for a garden. It is decided to put a pavement inside the entire border so that 64 square feet of the plot is left for flowers. How wide should the pavement be? Answer:_________feet

Solution

rectangular plot is 18ft X 18ft

area = 324 sq feet

( 18-2x) ( 18-2x) = 324 - 64

36x+36x - 4x^2 = 260

x = 5

x = 13

hence the pavement is 5 feet wide