SOLUTION: A rectangle is 5 cm longer than its width. If its width is x cm and its area is 14 cm2

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Question 1188894: A rectangle is 5 cm longer than its width. If its width is x cm and its area is
14 cm2

Found 2 solutions by ikleyn, greenestamps:
Answer by ikleyn(52781) About Me  (Show Source):
You can put this solution on YOUR website!
.

The dimensions are 7 cm and 2 cm.    ANSWER



Answer by greenestamps(13200) About Me  (Show Source):
You can put this solution on YOUR website!


If this problem is for a basic algebra class, then you will want to do something like this:

let x = width
then x+5 = length

The area (length times width) is 14:

x%28x%2B5%29=14
x%5E2%2B5x=14

It's a quadratic equation; get everything on one side and solve by factoring:

x%5E2%2B5x-14=0
%28x%2B7%29%28x-2%29=0
x=-7 or x=2

x = -7 makes no sense in the problem, so reject it; the solution is

width = x = 2
length = x+5 = 7

While that is a good exercise in algebra, note that the formal algebra doesn't help you solve the problem, because in factoring x%5E2%2B5x-14 you need to find two numbers whose difference is 5 and whose sum is 14 -- but that's what the original problem required you to do.