Uncle Wang surrounded a rectangular vegetable field with a 48-meter fence against the wall. The length-width ratio of this rectangle is 5: 2. What is the area of this vegetable field?

Solution: Let the length and width be 5m and 2m respectively.

According to the meaning of the question

5a+2a×2=48 (wall as width at this time)

9a=48

a= 16/3

Length = 80/3m

Width = 32/3m

Area = 80/3×16/3 =1280/9 m2.

or

5a×2+2a=48

12a=48

a=4

Length = 20m

Width = 8m

Area = 20× 8 = 160m2.

for reference only