Question 25422
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Subtraction means to add the opposite

1 + (-2)

To add numbers with unlike signs, we subtract the smaller absolute value
from the larger, and put on the sign of the number with the larger
absolute value.

1 has absolute value 1
-2 has absolute value 2

2 is larger than 1
We subtract 2-1 and get 1
Then we notice that -2 has the larger absolute value, and it has a
negative sign, so we put a negative sign on the 1, and the answer is

-1