Answer:
a. You have chosen 20 ft for the perimeter.
b. l = 10 - w
Explanation:
b. You are told to solve the formula for l. Presumably, you are to put your number in place of P.
20 = 2l + 2w
10 = l + w . . . . . divide by 2 (because we can. It simplifies the expression.)
To solve for l, we subtract w from both sides of the equation.
10 - w = l + w - w
10 - w = l . . . . . an expression for the length of the cage in terms of w