-13 + i
OK. Let's first get the sum of 5 - 9i and -4 + 7i. To add complex numbers, simply add their real parts and their imaginary parts separately. So
(5 - 9i) + (-4 + 7i) = ((5 + (-4)) + (-9 + 7)i) = 1 - 2i
And now we need to subtract 14 - 3i from that sum. So
(1 - 2i) - (14 - 3i) = (1 - 14) + (-2 - (-3))i = -13 + 1i = -13 + i
