What minus 0 equals 21?

Here we will show you how to calculate "What minus 0 equals 21?" using simple algebra.
For the sentence, "What minus 0 equals 21?", we can make it into an algebra equation as follows:
X - 0 = 21
Then, we solve for X. To solve for X, add 0 to both sides:
X - 0 + 0 = 21 + 0
Which makes:
X = 21
Thus, the answer to "What minus 0 equals 21?" is 21 as illustrated below:
21 - 0 = 21