Question

A rectangular sidewalk has an area of 57 feet. If the sidewalk is 3.8 feet wide, how long is it in feet?

Answer 1

The formula is A=L×W short for Area=Length×Width

57ft = L×3.8ft

57÷3.8=15 ft=L

The sidewalk is 15 ft long

Answer 2

Take the formula of a rectangle and use substition to fill in the information you already know.

A= LxW

57f = L x 3.8f

Now use the balance method to figure out what the length is. You're really just doing algebra. 

57f= L x 3.8f

57f ÷ 3.8 f = L x 3.8f ÷ 3.8f

15f= L

ANSWER: The length of the sidewalk in 15 feet.

CHECK:

A= L x W

A= 15f x 3.8f

A= 57 feet