Math
posted by Aniya on .
A 10gal aquarium is 3 in. higher than it is wide. Its length is 21 in, and its volume is 2730 in^3. What are the height and width of the aquarium?
x(x+3)......x^2+3x
21(x^2+3x)....
21x^2+63x2730.....
I am stuck.....I think I am doing it wrong. I have the answers but I don't know how to get there....Help!

Let x be the width. x = 3 is then the height.
21 x*(x+3) = 2730
x(x+3) = 130
x^2 +3x 130 = 0
(x10)(x+13) = 0
The only meaningful root is x = 10.