Alana incorrectly simplified the expression (-14a + 12) - (-10a + 13) as - 24a + 25 describe her error

The answer should be - 4a-1. This is because you have to open the box.

- (-10a+13)

Two negatives become positive so she should have had - 14+10 to make - 4 and 12-13 to make - 1. A negative and positive together, the negative always wins so that why you subtract.