Question

4x + 7y = 17
5x + 3y = 4
Penyelesaiaan sistem persamaan linier dua variabel .
= ???????

Answer 1

4x + 7y = 17      | kali 5       ........ (1)
5x + 3y = 4        | kali 4       ........ (2)

menjadi:

20x + 35y = 85
20x + 12y = 16
______________ -
        23 y  = 69
             y =
             y = 3

Jika y = 3, maka (kita ambil salah satu persamaan):

5x + 3y = 4
5x + 3.3 = 4
5x + 9 = 4
5x = 4-9
5x = -5
  x = 
  x = -1

Kesimpulan:

y = 3
x = -1