[m]\large x(Q) = \frac{x(M) + x(N)}{2}[/m]
[m]\large y(Q) = \frac{y(M) + y(N)}{2}[/m]
1) M(3; 6); N(x; y;); Q(0; 9)
[m]\large x(Q) = \frac{x(M) + x(N)}{2}[/m]
[m]\large 0 = \frac{3 + x}{2}[/m]
[m]\large x = -3[/m]
[m]\large y(Q) = \frac{y(M) + y(N)}{2}[/m]
[m]\large 9 = \frac{6 + y}{2}[/m]
[m]\large 6 + y = 18[/m]
[m]\large y = 12[/m]
N(–3; 12)
2) M(–2; –12); N(–8; 4); Q(x; y)
[m]\large x(Q) = \frac{x(M) + x(N)}{2} = \frac{-2 - 8}{2} = \frac{-10}{2} = -5[/m]
[m]\large y(Q) = \frac{y(M) + y(N)}{2} = \frac{-12 + 4}{2} = \frac{-8}{2} = -4[/m]
Q(–5; –4)
3) M(x; y); N(6; –2); Q(1; 2)
[m]\large x(Q) = \frac{x(M) + x(N)}{2}[/m]
[m]\large 1 = \frac{x + 6}{2}[/m]
[m]\large x + 6 = 2[/m]
[m]\large x = -4[/m]
[m]\large y(Q) = \frac{y(M) + y(N)}{2}[/m]
[m]\large 2 = \frac{y - 2}{2}[/m]
[m]\large y - 2 = 4[/m]
[m]\large y = 6[/m]
M(–4; 6)