Tolong yang bisa bantu pake caranya :

Mapel : Matematika
Bab : Sistem Persamaan Linear Tiga Variabel

Diketahui :
– 1/x + 1/y + 1/z = 3
– 3/x – 2/y – 4/z = – 3
– 2/x + 1/y – 4/z = – 1
– 1/x = a
– 1/y = b
– 1/z = c
– a + b + c = 3
– 3a – 2b – 4c = – 3
– 2a + b – 4c = – 1

Ditanya :
– Nilai x = …..?
– Nilai y = …..?
– Nilai z = …..?
– Nilai x + y + z = …..?

Penyelesaian :
– Nilai x :
a + b + c = 3
c = 3 – a – b

3a – 2b – 4c = – 3
3a – 2b – 4(3 – a – b) = – 3
3a – 2b – 12 + 4a + 4b = – 3
3a + 4a – 2b + 4b = – 3 + 12
7a + 2b = 9

2a + b – 4c = – 1
2a + b – 4(3 – a – b) = – 1
2a + b – 12 + 4a + 4b = – 1
2a + 4a + b + 4b = – 1 + 12
6a + 5b = 11

(7a + 2b = 9) × 5
(6a + 5b = 11) × 2

35a + 10b = 45
12a + 10b = 22
___________ —
23a = 23
a = 23/23
a = 1

1/x = a
1/x = 1
1 = 1 × x
1 = x
x = 1

– Nilai y :
7a + 2b = 9
7 + 2b = 9
2b = 9 – 7
2b = 2
b = 2/2
b = 1

1/y = b
1/y = 1
1 = 1 × y
1 = y
y = 1

– Nilai z :
c = 3 – a – b
c = 3 – 1 – 1
c = 1

1/z = c
1/z = 1
1 = 1 × z
1 = z
z = 1

– Nilai x + y + z :
x + y + z
= 1 + 1 + 1
= 3

Maaf Kalau Salah