Answer:
Length L = 17 ft.
Width W = 4 ft
Step-by-step explanation:
Area of a rectangle = L * W
Area = 68 ft²
W = 2L - 30
Area = L * W
68 = L * (2L - 30)
68 = 2L² - 30L
2L² - 30L -68 = 0 ( solve L by using quadratic equation)
-(-30) ± √ -30² - 4 * 2 * (-68)
L = -------------------------------------------
2 * 2
L = 17 ; L= - 2 therefore use L = 17 ft.
<u>solve for W:</u>
W = 2(17) - 30
W = 34 - 30
W = 4 ft
check:
68 = 17 * 4
68 = 68 ----- OK
Length=17
Width=4
Length=x
Width=2x-30
x(2x-30)=68
2x²-30x=68
2x²-30x-68=0
2(x²-15x-34)=0
2(x+2)(x-17)=0
So x equals either 17 or -2. Since it can’t be -2, x=17
Length=x=17
Width=2x-30=2*17-30=34-30=4
$56.67
$30+$21.50+$50=101.50
$101.50-$18=$83.50
$83.50-$26.83=$56.67
D. none of the above.
I believe that something is missing.
