Question

Please jawab hari ini dikumpul

Answer 1

Verified answer

Mapel : Matematika
Bab : Sistem Persamaan Linear Dua Variabel

Diketahui :
- 5/x - 3/y = 1
- 7/x + 3/y = 2
- 1/x = a
- 1/y = b
- 5a - 3b = 1
- 7a + 3b = 2

Ditanya :
- Nilai 1/x - 1/y = .....?

Penyelesaian :
- Nilai x :
5a - 3b = 1
7a + 3b = 2
________ +
12a = 3
a = 3/12
a = 1/4

1/x = a
1/x = 1/4
x = 4

- Nilai y :
5a - 3b = 1
5(¼) - 3b = 1
5/4 - 3b = 1
4(5/4 - 3b = 1)
5 - 12b = 4
- 12b = 4 - 5
- 12b = - 1
12b = 1
b = 1/12

1/y = b
1/y = 1/12
y = 12

- Nilai 1/x - 1/y :
1/x - 1/y
= 1/4 - 1/12
= 3 - 1/12
= 2/12
= 1/6

Jawaban : D. 1/6

Maaf Kalau Salah

Answer 2

Materi : Persamaan Linear Dua Variabel
Kelas : SMP dan SMA

5/x - 3/y = 1 ... Pers 1
7/x + 3/y = 2 ...Pers 2

#Eliminasi pers 1 dan 2 :
5/x - 3/y = 1
7/x + 3/y = 2
__________ +
12/x + 0 = 3
12/x = 3
12 = 3x
12/3 = x
4 = x

#Subsitusi x = 4 ke pers 1
5/x - 3/y = 1
5/(4) - 3/y = 1
-3/y = 1 - 5/4
-3/y = -1/4
-3 = -1/4y
-3 / -1/4 = y
12 = y

Sehingga x = 4 dan y = 12

Yang di tanya : 1/x - 1/y
= 1/x - 1/y
= 1/(4) - 1/(12)
= 2/12 (Di perkecil dengan di bagi 2)
= 1/6 Maka jawabannya adalah opsi d

Semoga membantu