The perimeter of the rectangle is 76 cm. Find its area if the width is less than the length by 4 cm.

Given:
Perimeter: 76 centimeters
Length: x.
Width: x-4.
Find the area.
Solution: Perimeter = (length + width) * 2, from here it follows that half of the perimeter will be the sum of the width and length.
1) 76/2 = 38.
2) compose the equation x + x-4 = 38. 2x = 38 + 4. 2x = 42. x = 21 centimeters length of the rectangle.
3) 21-4 = 17 centimeters width of the rectangle. Check: (21 + 17) * 2 = 38 * 2 = 76. The solution is correct.
4) find the area of the rectangle by the formula: S = length * width.
S = 21 * 17 = 357 square centimeters.
Answer: the area of the rectangle = 357 square centimeters.