Question

If one side of a square is increase by 10 units, the area of the rectangle formed is 3 times the area of the square. Find the area of the rectangle.

Answer 1

75 square units

Explanation:

(x+10)x=3x^2

x^2+10x=3x^2

10x=2x^2

5x=x^2

x=5

Plugging in 5 into either of the initial equations yields the answer.