=6÷﹙ 1- 1/4-3/4× 1/5﹚
=6÷﹙ 1- 1/4-3/20﹚
=6÷ 12/20
=6×20/ 12
= 10 (liter)
2. Solution: Let the side length of a square be x cm. Then the area of a strip is 4x cm 2.
5﹙x-4﹚=4x
5x-20=4x
5x-4x=20
x=20
4x=4×20=80
The area of each strip is 80 square centimeters.