Question 255837
Initially 6 x 5 = 30 sq cm
In the new case (x + 6)(x + 5)=90
x^2 + 11x + 30 = 90 or
x^2 + 11x - 60 = 0
(x - 4)(x + 15) = 0
x = 4 or -15
The number must be positive, so x=4
this gives 10 and 9 cm which give an area of 90 cm sq