Assuming that the water consumption does not exceed X cubic meters, 2.8 yuan will be charged per cubic meter. According to the water consumption and cost of Xiaoming's home in February, the equation is as follows: 2.8x+(238.5-231-x) * 4.8 = 26.
2.8X+36-4.8X=26
2X= 10
X=5
(2) How much water is paid in March?
250-238.5= 1 1.5 tons. If it exceeds 5 tons, the water fee payable is as follows:
5 * 2.8+(11.5-5) * 4.8 = 45.2 yuan.
(3) How many cubic meters of water did his family use in January?
Because if you use 5 tons of water a month, the tax payable is 5*2.8= 14 yuan, and the water fee of Xiaoming's family in January is 12.6 yuan, so his family's water consumption does not exceed 5 tons. The calculation formula is as follows: 12.6÷2.8=4.5 tons.