The width of the rectangle is 25 centimeters. How much will the width increase if its area increases from 30 to 35.

Let’s find the length of the rectangle from the formula:
S = a * b, where S is the area of the rectangle, a is the length of the rectangle, b is the width of the rectangle.
a = 30: 25 = 1.2 centimeters.
Knowing that the area has become 35 square centimeters, and the length remains the same 1.2 centimeters, you can find out the width of the resulting rectangle:
b = 35: 1.2 = 29.1666 centimeters.
Let’s find how much the width of the rectangle has increased:
29.1666 – 25 = 4.1666 centimeters.
Answer: the width of the rectangle has increased by 4.1666 centimeters.