Tolong yang bisa jawab :) 1. Diketahui sistem persamaan 2x + 3y + 4z = 20 x + 2y + 3z = 14 3x + y + 2z = 11 Nilai x,y, dan z berturut- turut adalah...

2x + 3y + 4z = 20 ...(i)
x + 2y + 3z = 14 ...(ii)
3x + y + 2z = 11 ...(iii)

Eliminasi (i) dan (ii)
2x + 3y + 4z = 20
x + 2y + 3z = 14 (x 2)

2x + 3y + 4z = 20
2x + 4y + 6z = 28
–––––––––––– –
-y - 2z = -8
y = 8 - 2z ... (iv)

Subtitusi pers.(iv) ke (ii)

x + 2(8 - 2z) + 3z =14
x + 16 - 4z + 3z = 14
x - z = -2 ... (v)

Subtitusi pers.(iv) ke (iii)

3x + 8 - 2z + 2z = 11
3x = 3
x = 1

Subtitusi x = 1 ke pers. (v)

x - z = -2
1 + 2 = z
z = 3

Subtitusi z = 3 ke pers. (iv)

y = 8 - 2z
y = 8 - 2(3)
y = 2

HP : {1 , 2 , 3}