Answer:
Step-by-step explanation:
Point 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\quad\quad y_B-3=3-1\\\\x_B=-3+8-3\qquad\qquad\ \wedge\qquad\quad y_B=2+3\\\\x_B=2\qquad\qquad\ \wedge\qquad\qquad y_B=5[/tex]