Question

Please

The length of a rectangle is three feet shorter than twice its width. If the area of the rectangle is 170ft^2, is what is the length of the rectangle?

Answer 1

Let the width be w. thus the length is (2w-3).
thus 170=w(2w-3)
170=2w^2-3w
0=2w^2-3w-170
Solve that quadratic to get the width w. Then calculate the length.
I hope that helps.

Answer 2

ok.... gimme a sec... solving

Answer 3

I have to logout, so I hope you got w=10.

Answer 4

yes.... thank you... solve by completing the square?

Answer 5

You're welcome. Yes, completing the square will work, but is quite a long process. I prefer using the quadratic formula.

Answer 6

really quick... whats the formula

Answer 7

completing the square i kept getting wrong answers

Answer 8

I recommend reading about both completing the square and the quadratic formula (which is essentially a short-cut of completing the square) here: http://tutorial.math.lamar.edu/Classes/Alg/SolveQuadraticEqnsII.aspx

Answer 9

thank you

Answer 10

You're welcome. Do you still want the quadratic formula?

Answer 11

\[x=(-b +/- \sqrt{b^2-4ac})/2a \]

Answer 12

That hasn't come out quite as it's supposed to, but you'll get the exact one in the link I've posted. Best wishes.