You know the cost per square foot of carpet and the dimensions of the bedroom; to find the cost of carpeting the entire room, first determine its area.
A = bh
A = 15(12)
A = 180
The area of the bedroom is 180 square feet. The cost of carpeting the entire bedroom will be the amount of square feet of the bedroom (its area) times the cost per square foot of carpet. Multiply the area by the cost per square foot.
180 × 22 = 3960
It will cost $3,960 to carpet the bedroom.