Question 1112022
Area = L x W = 28
L = 2W + 1 substitute for L above:
(2W + 1)W = 28 distribute the W (distributive property of multiplication)
2W^2 + W = 28
2w^2 + W - 28 = 0
rewrite like this:
-28 + W + 2W^2 = 0
now factor:
(-4 + -1W)(7 + -2W) = 0
take the left side:
-4 + -1W = 0
-1W = 4
-W = 4
W = -4
take the other equation, the one on the right:
7 + -2W = 0
-2W = -7
W = -7/-2
W = 3.5
Your answer is:
W = -4 or W = 3.5
The answer we are looking for is not negative, so let's try the 3.5 first:
L = 2W + 1
L = 2(3.5) + 1
L = 8
next:
L x W = 28
8 x 3.5 = 28 Correct
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Happy learning,
John