There are 64 black and white rabbits, of which black rabbits account for 25%. Later I bought some black rabbits. Now black rabbits account for 40% of the total number of black and white rabbits. How m

There are 64 black and white rabbits, of which black rabbits account for 25%. Later I bought some black rabbits. Now black rabbits account for 40% of the total number of black and white rabbits. How many black rabbits did you buy? I also bought 16 black rabbit.

Suppose you buy x more black rabbits,

There were 64 black and white rabbits, of which black rabbits accounted for 25%, and later some black rabbits were bought. Now black rabbits account for 40% of the total number of black and white rabbits.

Then it can be listed as:

X+64*25%=(64+X)*40%

By solving this equation, we can get X= 16.

So I bought 16 black rabbit.

Extended data:

There are five steps to solve a linear equation with one variable, namely, denominating, removing brackets, shifting terms, merging similar terms, and the transformation coefficient is 1. All steps are carried out according to the properties of algebraic expressions and equations.

To solve this equation

For example:

If you remove the denominator, you will get:

Without parentheses, you get:

To move an item, you must:

Merge similar items, get: (usually abbreviated as "merge, get:")

The coefficient becomes 1, and we get: