Answer:
M(-a, b)
Step-by-step explanation:
Use the formula of a midpoint:
[tex]\left(\dfrac{x_1+x_2}{2},\ \dfrac{y_1+y_2}{2}\right)[/tex]
We have the points P(-2a, 0) and Q(0, 2b). Substitute:
[tex]x=\dfrac{-2a+0}{2}=\dfrac{-2a}{2}=-a\\\\y=\dfrac{0+2b}{2}=\dfrac{2b}{2}=b[/tex]
