Question 472854
In a rectangle, the length is three more than one half of the width.
L = {{{1/2}}}W + 3
:
If the area is 56, what is the width?
L * W = 56
Replace L with ({{{1/2}}}W + 3)
({{{1/2}}}W + 3) * W = 56
{{{1/2}}}W^2 + 3W = 56
Get rid of the fraction, mult eq by 2
W^2 + 6W = 112
A quadratic equation
W^2 + 6W - 112 = 0
You can find W using the quadratic formula; a=1, b=6, c=-112, but:
this will factor to
(W+14)(W-8) = 0
the positive solution
W = 8
then "the length is three more than one half of the width." therefore:
L = {{{1/2}}}(8) + 3
L = 7
:
:
Check by finding the area with these values: 7 * 8 = 56