The length of a rectangle is 13 centimeters less than five times its width. Its area is 28 square centimeters. Find the dimensions of the rectangle.

Sagot :

Answer:

Length = 7cm

Width = 4cm

Step-by-step explanation:

The area of a rectangle is calculated as:

Length × Width

The length of a rectangle is 13 centimeters less than five times its width.

This is expressed Mathematically as:

L = 5W - 13

Its area is 28 square centimeters.

Therefore:

28cm² = 5W - 13 × W

28 = (5W - 13)W

28 = 5W² - 13W

Hence,

5W² - 13W - 28 = 0

We factorise

5W² - 20W - 7W - 28 = 0

5W(W - 4) + 7(W - 4) = 0

(5W + 7)(W - 4) = 0

5W + 7 = 0

5W = -7

W = -7/5

W - 4 = 0

W = 4 cm

Solving for the length

L = 5W - 13

L = 5 × 4 cm - 13

L = 20 cm - 13 cm

L = 7 cm

Therefore, the dimensions of the rectangle is:

Length = 7cm

Width = 4cm