Answer
$-3$
Work Step by Step
The numbers being added have different signs.
To add these numbers, perform the following steps:
(1) Subtract the bigger absolute value by the smaller absolute value to obtain:
$|-10| - |7| = 10-7 = 3$
(2) The sum will have the same sign as the number with the bigger absolute value.
Since $|-10| \gt |7|$, then the sum will be negative.
Thus,
$7+(-10) = -3$