Pls explain

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Pls explain

by Nycgrl » Sun Jun 22, 2008 4:49 pm
The surface area of a square tabletop was changed so that one of the dimensions was reduced by 1 inch and the other dimension was increased by 2 inches. What was the surface area before these changes were made?
(1) After the changes were made, the surface area was 70 square inches.
(2) There was a 25 percent increase in one of the dimensions.

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by atlantic » Mon Jun 23, 2008 1:29 am
Let 'L' be the original side length of the square tabletop.

Changed dimensions are L-1 and L+2

(1) says that (L-1)(L+2)=70, so you can calculate L, SUFF

(2) says that L+2=1,25L, so you can calculate L, SUFF

Answer D.