SOLUTION: a rectangle 15 cm by 30 cm is increased on all sides by the same amount. its area increased by 144cm2. by how much is each dimension increased?

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Question 663128: a rectangle 15 cm by 30 cm is increased on all sides by the same amount. its area increased by 144cm2. by how much is each dimension increased?
Answer by larrypizzu (5) About Me  (Show Source):
You can put this solution on YOUR website!
Note:
Area of a rectangle = L * B
Initial area before increment=30cm*15cm=450sqcm
New dimension is (x+30)cm by (x+15)cm
(X+30)(X+15)=450+144
X^2+45X+450=594
X^+45X-144=0
(X-3)(X+28)=0
X=3 or -28
Since it is distance our answer will be the positive value.
Answer=3cm