How to solve the fourth problem on page 72 of the first volume of the sixth grade mathematics supplementary exercise in Jiangsu Education Press?
4. solution: there is a production platform for x people.
20X=(56-X)* 15
20X=840- 15x
20x+ 15x=840
35x=840
x=840/35
x=24
56-24=32 (person)
A: 24 people produce desks and 32 people produce square stools.