2x-y=7...1 dan 3y+2y=1...2

[tex]2x - y = 7 \\ y = 2x - 7.....(1) \\ substiusikan \: (1) \: ke \: (2) \\ 3x + 2(2x - 7) = 1 \\ 3x + 4x - 14 = 1 \\ 7x = 15 \\ x = \frac{15}{7} \\ y = 2( \frac{15}{7} ) \\ = \frac{30}{7} [/tex]

cara 1 :
dari persamaan 2 didapat
3y + 2y = 1
5y = 1
y = 1/5

2x - y = 7
2x - 1/5 = 7
10x - 1 = 35
10x = 36
x = 3,6

cara 2 :
y = 2x - 7

5y = 1
5(2x -7) = 1
10x - 35 = 1
10x = 36
x = 3,6