a rectangle has an area of 288 cm(square). if the width is decreased by 1 cm and the length increased by 1 cm, the area would decrease by 3 cm(square). Find the original dimensions of the rectangle.

2. Originally Posted by Ilsa
a rectangle has an area of 288 cm(square). if the width is decreased by 1 cm and the length increased by 1 cm, the area would decrease by 3 cm(square). Find the original dimensions of the rectangle.
I'm not really an expert in this, but here's how I do it.

L X W = 288

(L+1) (W-1) = 285
LW - 1L + 1W - 1= 285
LW - 1L + 1W = 286

then i do this:

.....LW - 1L + 1W = 286
(-) LW = 288
----------------------------
..... -L + W = -2
..... W = -2 + L

then i substitute to L x W = 288

L x W = 288
L (-2+L) = 288
-2L + L2 = 288
L2 -2L - 288 = 0
(L-18)(L+16) = 0
L = 18
L = -16 (this one is rejected because a rectangle cannot have negative sides)

then substitute to get the value of W
L x W = 288
18 x W = 288
18W = 288
W = 16

That's how i do it. Sorry if I don't know how to put into math code.

3. Originally Posted by reiward
I'm not really an expert in this, but here's how I do it.

That's how i do it. I don't know about the negative answers though if it's acceptable.
Just ignore the negative values. You can't have a negative length or width.

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# a rectangle has an area of 288 cm2. if the width is decreased by 1 cm and the length increased

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