# One side of the rectangle was doubled, and the other was reduced by 30 percent.

**One side of the rectangle was doubled, and the other was reduced by 30 percent. Has its area increased or decreased, by what percentage?**

Let us denote the length of side number one of a given rectangular quadrangle by a, and the length of side number two of a given rectangular quadrilateral by b.

Then the area of this rectangular quadrangle will be a * b.

If side number one of this rectangular quadrangle is doubled, and the other is reduced by 3 tens of percent, then the length of side number one will be 2a, and the length of side number two will be b – (30/100) * b = b – (3/10) * b = b – 0.3 * b = 0.7 * b, and the area of the resulting rectangle will be 2a * 0.7 * b = 1.4 * a * b.

Therefore, the area of the original quadrangle will increase by:

100 * (1.4 * a * b – a * b) / (a * b) = 100 * 0.4 * a * b / (a * b) = = 100 * 0.4 = 40%.

Answer: the area will increase by 40%.