(1) clothing profit = number of people × number of clothes per person per day × profit per piece.

(2) Profit of surplus cloth = direct selling price per meter × surplus cloth.

(3) Clothing profit+surplus profit = 1 1800, and the equation is listed.

(4) When all woven fabrics are used to weave clothes, the profit is the biggest.

explain

( 1)P=4×25x= 100x。

(2)Q = 2[30( 150-x)-4× 1.5x]=-72x+900。

(3) According to the meaning of the question,100x-72x+900 =11800.

X = 100。 Arrange 100 workers to make clothes a day, and the profit is 1 1800 yuan.

(4) 4× 1.5x = 30x ( 150-x)。

The solution is x = 125.

10×125× 300 = 3.75×106 (yuan).