jika X dan Y memenuhi sistem persamaan 3 x - y = 16 dan X + Y = 12 nilai x + 2 y adalah... #PlisssJawabDgnCptDanTepat

x + y = 12
y = 12 - x

3x - y = 16
3x - (12-x) = 16
3x - 12 + x = 16
4x = 16 + 12
4x = 28
x = 28/4 = 7

y = 12 - x
y = 12 - 7
y = 5

Sehingga nilai
x + 2y = 7 + 2*5
= 7 + 10
= 17

Semoga membantu :-)

Pembahasan :

x + y = 12
y = 12 - x

3x - y = 16
3x - (12 - x) = 16
3x - 12 + x = 16
4x = 28
x = 7

y = 12 - x
= 12 - 7
= 5

x + 2y = 7 + 2(5)
= 7 + 10
= 17