25 plus what equals 15?

This is how to calculate "25 plus what equals 15?" In other words, 25 plus a number equals 15. What is that number? We start by converting this word problem into an equation where "what" is what we want to solve:

25 + what = 15

To solve this equation, we first add -25 to each side of the equal sign like this:

25 - 25 + what = 15 - 25

Then, we do the calculation to get the answer to "25 plus what equals 15?" as follows:

What = -10

The answer to "25 plus what equals 15?" is -10. You know this answer is correct because 25 plus -10 equals 15.

Plus What Equals Calculator
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