posted by tasha on .
Suppose that the width of a rectangle is 5 inches shorter than the length and that the perimeter of the rectangle is 50 inches. The formula for the perimeter of a rectangle is P=2L+2W.
a) Set up an equation for the perimeter involving only L, the length of the rectangle.
B) Solve this equation algebraically to find the length of the rectangle. Find the width as well.
W = L - 5
50 = 2L + 2W
Substitute L - 5 for W in the second equation and solve for L. Put that value in the first equation to find W. Check by putting both values into the second equation.