A. 2x+y-3=0
B.2x-y+3=0
C.x-2y+3=0
D.x+2y-3=0
Persamaan Garis diatasi Yang Melalui Titik(1,1) dan (-1,2)
Tolong Jawab pakai caranya juga
Pilihlah Salah satu jawaban yang benar.
Penyelesaian :
titik (x,y)
titik 1 (1,1)
titik 2 (-1,2)
Untuk mengetahui persamaan yang tepat harus dicek satu persatu.
A. 2x + y – 3 = 0
(1,1) 2(1) + 1 – 3 = 0 ==> 2 + 1 – 3 = 0 ==> 3 – 3 = 0 ==> 0 = 0
(-1,2) 2(-1) + 2 – 3 = 0 ==> -2 + 2 – 3 = 0 ==> 0 – 3 = 0 ==> -3 = 0
Jawaban salah.
B. 2x – y + 3 = 0
(1,1) 2(1) – 1 + 3 = 0 ==> 2 – 1 + 3 = 0 ==> 1 + 3 = 0 ==> 4 = 0
(-1,2) 2(-1) – 2 + 3 = 0 ==> -2 – 2 + 3 = 0 ==> -4 + 3 = 0 ==> -1 = 0
Jawaban Salah.
C. x – 2y + 3 = 0
(1,1) 1 – 2(1) + 3 = 0 ==> 1 – 2 + 3 = 0 ==> -1 + 3 = 0 ==. 2 = 0
(-1,2) -1 – 2(2) + 3 = 0 ==> -1 – 4 + 3 = 0 ==> -5 + 3 = 0 ==> -2 = 0
Jawaban Salah.
D. x + 2y – 3 = 0
(1,1) 1 + 2(1) – 3 = 0 ==> 1 + 2 – 3 = 0 ==> 3 -3 = 0 ==> 0 = 0
(-1,2) -1 + 2(2) – 3 = 0 ==> -1 + 4 – 3 = 0 ==> 3 – 3 = 0 ==> 0 = 0
Jawaban Benar.
Jadi, persamaan garis yang melalui titik (1,1) dan (-1,2) adalah x + 2y – 3 = 0 (Jawabannya D)