The length of the rectangle is 20m longer than its width. If the length of the rectangle is reduced by 10m

The length of the rectangle is 20m longer than its width. If the length of the rectangle is reduced by 10m and the width is increased by 6m, then its area will increase by 12m2. Find the sides of the rectangle.

1. Take the width of the rectangle as x. Its length is (x + 20) m.

2. The area of the rectangle is x x (x + 20) = (x ^ 2 + 20x) m ^ 2.

3. Changed width (x + 6) m.

Modified length (x + 20 – 10) = (x + 10) m.

4. The area of the rectangle is (x + 6) x (x + 10) = (x ^ 2 + 10x + 6x + 60) m ^ 2.

5. We make the equation:

x ^ 2 + 10x + 6x + 60 – x ^ 2 – 20x = 12;

– 4x = – 48; x = 12 m – the width of the rectangle.

12 + 20 = 32 m – the length of the rectangle.

Answer: the width of the rectangle is 12m, the length of the rectangle is 32m.