Andrew M. answered • 07/13/15
Tutor
New to Wyzant
Mathematics - Algebra a Specialty / F.I.T. Grad - B.S. w/Honors
When we set up and solve the quadratic equation for this problem we discard the negative
values in the final answer because length and width of the sides of a rectangle are always
considered to be a positive number. If the problem is worked to the correct solution then
the final answer is the rectangle is 3 by 8.
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We can check that easily enough.
x = 3
2x+2 = 8
and (3ft)(8ft) = 24 ft2
The only reason she is incorrect is because she said the rectangle could also be -4 by -6
Which by the way does also satisfy the equation.
Andrew M.
-4 by -6 does fit 'x and 2x +2'
2(-4)+2 = -8
It also fits 24 ft2 since (-4)(-6) = 24
The only reason she was wrong is that the length
and width of a rectangle cannot be a negative value.
Thus, while both 3 by 8 and -4 by -6 fit the
stated parameters, the only correct answer is
3 by 8
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07/13/15
Andrew M.
Correction..., typo...,
2(-4)+2=-6
so -4 by -6 does fit x and 2x+2
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07/13/15
David W.
07/13/15