1) The cost per square meter of the bottom and wall of the pond is X yuan and Y yuan respectively.

Because when the pool is 6M long, 4M wide and 2M deep, the pool bottom area is 6 * 4 = 24 square meters, and the pool wall is 6 * 2 * 2+4 * 2 * 2 = 24+ 16 = 40 (square meters).

At this time, the cost is 6080 yuan;

So the equation is: 24x+40y = 6080.

Because the swimming pool is 6 meters long, 2 meters wide and 4 meters deep, the pool bottom area is 6 * 2 = 12 square meters, and the pool wall is 6 * 4 * 2+4 * 2 = 48+ 16 = 64 (square meters).

At this time, the cost is 6560 yuan.

So we get the equation: 12x+64y = 6560.

Composition equation:

{24X+40Y=6080

{ 12X+64Y=6560

Solution:

{X= 120

{Y=80

Answer: The cost per square meter of the pond bottom and the pond wall is 1.20 yuan and 80 yuan respectively.

2)

If the completed swimming pool is 4 meters long, 2 meters wide and 6 meters deep.

The cost is:

4*2* 120+(6*4*2+6*2*2)*80

= 6720 (yuan)

Because the completed pool is 6 meters long, 4 meters wide and 2 meters deep, the cost is 6080 yuan.

The completed pool is 6 meters long, 2 meters wide and 4 meters deep, and the cost is 6560 yuan.

And 6080 < 6560 < 6720.

Therefore, among the three schemes, the scheme with a pool length of 6M, a pool width of 4M and a pool depth of 2M has the lowest cost.

Jiangsu Wu Yunchao wishes you academic progress.