Answer:
length = 9 in ; width = 4 in
Explanation:
1) formula of the area of a rectangle
A = base x width
2) write an equation with the given informations:
w x (3w-3) = 36
3) solve the equation
- multiply W by 3w and -3
3w^2 -3w = 36
- divide the two members by 3
w^2 - w = 12
- add up -12 at the two members
w^2-w -12 = 12 -12
w^2 - w - 12 = 0
- find two numbers whose sum is -1 and whose product is -12 and factorise the equation
(w-4)(w+3) = 0
- find the two solutions
w-4 = 0
w = 4
w+3 = 0
w = -3
4)remember that a length can’t be negative.
w = 4 is the only solution
5) find the length
4x3 - 3 = 9