SOLUTION: The dimension of a rectangle are 6cm x 10cm. A new rectangle is formed by increasing each dimension by the same amount. The area of the new rectangle is 80cm^2 more than the area

Algebra ->  Rectangles -> SOLUTION: The dimension of a rectangle are 6cm x 10cm. A new rectangle is formed by increasing each dimension by the same amount. The area of the new rectangle is 80cm^2 more than the area       Log On


   



Question 1019932: The dimension of a rectangle are 6cm x 10cm. A new rectangle is formed by increasing each dimension by the same amount. The area of the new rectangle is 80cm^2 more than the area of the original rectangle. Find the dimensions of the new rectangle.
This is my solution:
(10x6)+80=(x+10)(x+6)
60+80 =x^2+16x+60
140 = x^2 +16x +60
140-140 =x^2 +16x +60-140
0 =x^2 +16x -80
(x+20)(x-4)

Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
New dimensions, each is increased an additional x; the area of the NEW rectangle is (10+2x)(6+2x)=6*10+80.

Solve this equation for x:
%282x%2B10%29%282x%2B6%29=6%2A10%2B80


2%28x%2B5%29%2A2%28x%2B3%29=6%2A10%2B2%2A2%2A20

4%2A%28x%2B5%29%28x%2B3%29=140

4%28x%2B5%29%28x%2B3%29=2%2A2%2A35

%28x%2B5%29%28x%2B3%29=35--------------continue......