minta bantuan lagi:)

B(-1,4)
C(2,-2)

[tex] x_{1} = -1[/tex]
[tex] x_{2} = 2[/tex]
[tex] y_{1} = 4[/tex]
[tex] y_{2} = -2[/tex]

pers. garis:
[tex] \frac{x - x_{1} }{ x_{2} - x_{1} } = \frac{y - y_{1} }{ y_{2} - y_{1} } [/tex]
[tex] \frac{x + 1}{2 + 1} = \frac{y - 4}{-2 - 4} [/tex]
[tex] \frac{x + 1}{3} = \frac{y - 4}{-6} [/tex]
[tex]-6x-6 = 3y-12[/tex]
[tex]6 = 6x+3y[/tex]
[tex]2x + y = 2[/tex]

A(3,a) x=3
[tex]2(3) +y = 2[/tex]
[tex]y = -4[/tex]