Solution: 22 ≤ x ≤ 30 ... 4 points.
Since x is an integer, ∴x takes 22, 23, 24, 25, 26, 27, 28, 29 and 30.
∴ Assembling two kinds of fitness equipment (Type A and Type B) * * * There are nine assembly schemes. ..................................................................... scored 5 points.
(2) Total assembly cost: y = 20x+ 18 (40-x) = 2x+720. .............................................................................................................................
∵ k = 2 > 0, ∴y increases ............................................................................. by 8 points with the increase of x.
∴ When x = 22, the total assembly cost is minimum, and the minimum assembly cost is 2× 22+720 = 764 yuan.
The assembly scheme with the lowest total assembly cost: assemble 22 A-type equipment and 18 B-type equipment. .......................................................................................................................................
leave out