SOLUTION: The width of a rectangle is nine less than the length. If the sides of the rectangle are all increased by two, the area is 70. Find the original dimensions. In this I have the

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: The width of a rectangle is nine less than the length. If the sides of the rectangle are all increased by two, the area is 70. Find the original dimensions. In this I have the       Log On


   



Question 696124: The width of a rectangle is nine less than the length. If the sides of the rectangle are all increased by two, the area is 70. Find the original dimensions.
In this I have the answers to it, 14 and 5, but I am confused on how to solve it if you could please help me, Thank you very much.

Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!
The width of a rectangle is nine less than the length. If the sides of the rectangle are all increased by two, the area is 70. Find the original dimensions.
In this I have the answers to it, 14 and 5, but I am confused on how to solve it if you could please help me, Thank you very much.

Let the length = L
Then width = L – 9
Increasing the length by 2 results in a new length of L + 2
Increasing the width by 2 results in a new width of L – 9 + 2, or L - 7
Therefore, (L + 2)(L – 7) = 70

L%5E2+-+5L+-+14+=+70

L%5E2+-+5L+-+14+-+70+=+0

L%5E2+-+5L+-+84+=+0

(L + 7)(L - 12) = 0
L = - 7 (ignore as measurement CAN neither be negative, nor 0)

L, or original length = 12 units
Width = 12 – 9, or 3 units

Original dimensions: highlight_green%2812_by_3%29

14 and 5 are the new dimensions, after each side of the rectangle has been altered.

You can do the check!!

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