When a = 3i - 2j, and b = -4i + 10j. Plug in the corresponding terms with the corresponding variables.
(-4i + 10j) - (3i - 2j)
Distribute the negative to each variable in the second parenthesis
- (3i - 2j) = -3i + 2j
Simplify.
-4i + 10j -3i + 2j
-7i + 12j
-7i + 12j, or (A) is your answer
hope this helps