what are the dimensions of a rectangle whose length is 4 more than twice the with and whose perimeter is 3 less than 7 times the width

w = width

l = 2w+4

p = 7w-3

P = 2 (l+w)

substitute in p = 7w-3 and l = 2w+4

7w-3 = 2 (2w+4+w)

combine like terms

7w-3 = 2 (3w+4)

distribute

7w-3 = 6w + 8

subtract 6w from each side

w-3 = 8

add 3 to each side

w = 11

l = 2w + 4

l = 2 (11) + 4 = 22+4 = 26

P = 7w-3 = 7*11-3 = 77-3 = 74