Answer:
length 17 feet
width 7 feet
Step-by-step explanation:
Let w represent the width. Then the length is 2w+3, and the perimeter is ...
P = 2(L +W)
48 = 2((2w+3) +w) = 6w +6
42 = 6w
7 = w . . . . . . . . width
(2w+3) = 17 . . . length
The length of the garden is 17 feet; its width is 7 feet.