The perimeter of the rectangle is 100 cm. What are the length and width of the rectangle if the length is 4 times the width?

Let’s solve this problem using the equation.

Let the width of the rectangle be x centimeters, then its length is 4 * x centimeters. We know that the perimeter of the rectangle is 100 centimeters. we compose the equation:

2 * (x + 4 * x) = 100 (in order to find an unknown factor, you need to divide the product by a known factor);

x + 4 * x = 100: 2;

x + 4 * x = 50;

x * (1 + 4) = 50;

x * 5 = 50;

x = 50: 5;

x = 10 centimeters – the width of the rectangle;

4 * 10 = 40 centimeters – the length of the rectangle.

Answer: 10 centimeters; 40 centimeters.