tentukan persamaan garis lurus yang melalui dua titik berikut A. (-2,4)dan (2,8) B. (2,5)dan(5,8) C. (4,1) dan (-2,11)

Mapel       : Matematika
Kategori   : Persamaan Garis Lurus
Kelas        : SMP / MTs kelas VIII
Semester : Ganjil


Pembahasan:

Soal nomer a.
[tex] \frac{y-y_1}{y_2-y_1} = \frac{x-x_1}{x_2-x_1} [/tex]
[tex] \frac{y-4}{8-4} = \frac{x+2}{2+2} [/tex]
[tex] \frac{y-4}{4} = \frac{x+2}{4} [/tex] (4)
[tex] y-4 = x+2[/tex]
[tex] x-y+6 = 0[/tex]

Soal nomer b.
[tex] \frac{y-y_1}{y_2-y_1} = \frac{x-x_1}{x_2-x_1} [/tex]
[tex] \frac{y-5}{8-5} = \frac{x-2}{5-2} [/tex]
[tex] \frac{y-5}{3} = \frac{x-2}{3} [/tex] (3)
[tex] y-5=x-2[/tex]
[tex] x-y+3=0[/tex]

Soal nomer c.
[tex] \frac{y-y_1}{y_2-y_1} = \frac{x-x_1}{x_2-x_1} [/tex]
[tex] \frac{y-1}{11-1} = \frac{x-4}{-2-4} [/tex]
[tex] \frac{y-1}{10} = \frac{x-4}{-6} [/tex]
[tex] -6(y-1) = 10(x-4)[/tex]
[tex] -6y+6 = 10x-40[/tex] (: 2)
[tex] -3y+3 = 5x-20[/tex]
[tex] 5x+3y-23 = 5x-20[/tex]