Let these two masses be a and b.

One is placed on the right and the other on the left, and the magnification and reduction ratio are the same. So the product of a and b is constant, equal to 29*8=232, so just solve the equation:

a+b=30

a*b=232

How to solve this equation group with sum and product? According to David's theorem, if A and B satisfy the above equation, they are exactly the two roots of x 2-30x+232 = 0. This question is really good. It examines all kinds of knowledge points, but don't be busy. The wonderful thing is below-

That unary quadratic equation has no real root, because the discriminant 30 2-232 * 4 < 0, so as a mathematical problem, this problem has no solution.

Unless you also take modern physics. This special material is very special. When it is cut, it changes in the nucleus, absorbs a lot of energy, and adds some mass according to the law of conservation of mass and energy, which is possible. Junior high school only talks about classical physics, so the last paragraph is pure nonsense.