SOLUTION: A rectangle is drawn so that the width is 3 feet shorter than the length. The area of the rectangle is 70 square feet. Find the length of the rectangle.

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Question 1182600: A rectangle is drawn so that the width is 3 feet shorter than the length. The area of the rectangle is 70 square feet. Find the length of the rectangle.
Answer by ikleyn(52776) About Me  (Show Source):
You can put this solution on YOUR website!
.

Your equation is 


    L*(L-3) = 70.


Simplify and reduce it to the standard form of a quadratic equation.


Then solve it using the quadratic formula or factoring (both work in this case).


ANSWER.  The length is 10 inches.


Also, you may guess the answer mentally without using any equation/equations.

Since the left side of the equation is monotonically increasing function of the length L,
the guessed solution is UNIQUE: there is NO another solution.