Answer:
B(-2, -8)
Step-by-step explanation:
M being midpoint of AB means:
[tex]x_B-x_M=x_M-x_A\qquad\quad\ \wedge\qquad y_B-y_M=y_M-y_A\\\\x_B-3=3-8\qquad\quad\wedge\qquad\quad y_B-(-2)=-2-4\\\\x_B-3=-5\qquad\quad\ \wedge\qquad\quad y_B+2=-6\\\\x_B=-5+3\qquad\quad\ \wedge\qquad\quad y_B=-6-2\\\\x_B=-2\qquad\qquad\ \wedge\qquad\qquad y_B=-8[/tex]
