When the sum of the complex numbers 3 plus 2I and 6 - 4I is graphed in which quadrant does it lie?

3+2i + 6-4i = 9-2i

The real part of this number is positive, therefore it lies in Q1 or Q4.

The imaginary part is negative, therefore it is in Q3 or Q4.

Q4 is the common possibility, therefore 9-2i is in Q4.