SOLUTION: The legnth of a rectangle is 15 cm more than its width. A blue rectangle which is 5 cm wider and 2 cm shorter than the red one, has a perimeter 72 cm. Find the dimensions of each r

Click here to see ALL problems on Graphs

Question 130456This question is from textbook
: The legnth of a rectangle is 15 cm more than its width. A blue rectangle which is 5 cm wider and 2 cm shorter than the red one, has a perimeter 72 cm. Find the dimensions of each rectangle. This question is from textbook

Answer by kimboo(4) (Show Source):
You can put this solution on YOUR website!
let w = width of red rectangle
let w + 15 = length of red rectangle
let w - 2 = width of blue rectangle
let (w + 15) + 5 = length of blue rectangle
perimeter of the blue rectangle is 72 cm
P = 2*l = 2*w
72 = 2(w + 15 + 5) + 2(w - 2) (substitute perimeter and expressions for length and width of blue rectangle)
72 = 2w + 30 + 10 + 2w - 4 (use distributive property to solve equation)
72 = 4w + 36 (combine like terms)
72 - 36 = 4w + 36 - 36 (subtract 36 from each side of equation)
36 = 4w
36/4 = 4w/4 (divide each side of equation by 4)
9 = w (width of red rectangle is 9 cm)
w + 15 = 9 + 15 = 24 (length of red rectangle is 24 cm)
w - 2 = 9 - 2 = 7 (width of blue rectangle is 7 cm)
(w + 15) + 5 = 9 + 15 + 5 = 29 (length of blue rectangle is 29 cm)