c.
Step-by-step explanation:
from the expression (9 + 3i) - (-4 + i);
STEP 1: multiply (-4 + i) by the minus sign before it.
we have +4 - i as the result.
we are left now with:
9+3i+4-i.
STEP 2: grouping those with same values,
9+4+3i-i= 13+2i
n
step-by-step explanation: