Answer:
L = 2r + 3
Step-by-step explanation:
Given parameters:
Area of rectangle = 14r + 21
Width of the rectangle = 7ft
Unknown:
Length of the rectangle = ?
Solution:
If the length of the rectangle is designated as L;
Area of a rectangle = Length x width
Now insert the parameters:
14r + 21 = L x 7
L =
L = 2r + 3