1 The living room of Beibei s house is rectangular, and according to the original plan, square brick

Solution: (1) Set up a square brick with a side length of 5 decimeters to pave x blocks, 4 4 250 = 5 5 x, 25x = 4000, x = 4000 25, x = 160, answer: 160 square bricks with a side length of 5 decimeters are used to pave it

2) The area of Xiaofang's living room: 4 4 250 = 4000 (square decimeters) = 40 square meters, the amount of money spent with square bricks with a side length of 4 decimeters: yuan), manual fees:

13 40 = 520 (yuan), the total amount of money: 3200 + 520 = 3720 (yuan);

The amount of money spent with a square brick with a side length of 5 decimeters: 22 160 = 3520 (yuan), manual cost: 8 40 = 320 (yuan), the total amount of money:

3520 + 320 = 3840 (yuan), 3720 3840, so it is more appropriate to choose a square brick with a side length of 4 decimeters

Answer: It is more appropriate to choose square bricks with a side length of 4 decimeters

1. （4*4）/（5*5）=x/250

Solution: x=160