a is enough for a unit quantity of water.

You may find it difficult to understand this kind of topic when you are new to it. Let's give you an example. I hope you can understand it.

if the pesticide residue on vegetables is washed with water, it is assumed that the ratio of the pesticide residue on vegetables to the pesticide residue before this washing is 1/4(1+x) 1. The existing 6 kg of water with a(a≥2) unit can be washed once, or it can be washed twice after the level is divided into two parts, or the water content can be reduced to 2 kg/3 a.

I have replaced the original formula of A and X above you with concrete numbers, so it's easier to understand. Please list the equations with concrete formulas and replace them with letters.

this is algebra, which uses letters instead of specific numbers, just like a formula. As long as the numbers that meet the conditions replace A and X, it can be applied to concrete practice.

study math well, math is very important. Come on