<PRE><B>Question 309952</B>
let the width be x
length will be 5x-31

Area = L*W

72 = x(5x-31)
72=5x^2-31x
5x^2-31x-72=0
.
x1,x2 the roots of the equation will be

x1= 31+sqrt(-31^2-4*5*-72) / 2*5

x1= 31 +sqrt(-31^2 +1440) /10
x1= 8

x2 = -1.8

x2 is negative
So width = 8 cms
Then length will be 9cms</PRE>