SOLUTION: A rectangle has an area of 2x^2 + 2x - 112. a) If one side is (x -7) cm, show that the perimeter is 6(x +3)cm. b) Hence or otherwise, find the range of possible values for x

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Question 1119010: A rectangle has an area of 2x^2 + 2x - 112.
a) If one side is (x -7) cm, show that the perimeter is 6(x +3)cm.
b) Hence or otherwise, find the range of possible values for x
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
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A rectangle has an area of 2x^2 + 2x - 112.
a) If one side is (x -7) cm, show that the perimeter is 6(x +3)cm.
b) Hence or otherwise, find the range of possible values for x
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(b)
Range? Possible x values - first find the roots....
2x%5E2%2B2x-112=0
x%5E2%2Bx-56=0
%28x-7%29%28x%2B8%29=0
Only positive factors allowed.
highlight_green%28x%3E7%29


(a)
The other side is %282x%5E2%2B2x-112%29%2F%28x-7%29=2x%2B16.
Perimetr: 2%282x%2B16%29%2B2%28x-7%29
4x%2B32%2B2x-14
6x%2B18
6%28x%2B3%29