SOLUTION: A rectangle is 6 inches longer than it is wide. It has an area of 216-squared inches. What are the dimensions of the rectangle?

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Question 303759: A rectangle is 6 inches longer than it is wide. It has an area of 216-squared inches. What are the dimensions of the rectangle?
Answer by graphmatics(170) About Me  (Show Source):
You can put this solution on YOUR website!
If x is the width of the rectangle and y is the length then x*y=216. We also have y=x+6 so
x*(x+6)=216
x^2+6x-216=0
so using the quadratic formula to solve for x we get:

x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
x+=+%28-6+%2B-+sqrt%28+6%5E2-4%2A1%2A-216+%29%29%2F%282%2A1%29+
x+=+%28-6+%2B-+sqrt%28+900+%29%29%2F%282%29+
x+=+%28-6+%2B-+30%29%2F%282%29+
x+=+%2824%29%2F%282%29+
x+=+12+
to find the length of the rectangle we use the expression
y+=+x%2B6+
y+=+18+