Question

Persamaan linear dua variabel

1) 5/x + 4/y = 13
3/x - 2/y = 21

2) 1/x + 4/y = 12
3/x + 1/y = 14

Answer 1

5/x + 4/y = 13
3/x - 2/y = 21
misal 1/x = a dan 1/y = b
5a + 4b = 13 (x1) --> 5a + 4b = 13
3a - 2b = 21 (x2) --> 6a - 4b = 42 +
                                   11a = 55 --> a = 5
5.5 + 4b = 13
4b = 13 - 25
4b = -12
b = -3
a = 5 --> 1/x = 5 --> x = 1/5
b = -3 --> 1/y = -3 --> y = -1/3


1/x + 4/y = 12 --> a + 4b = 12 (x3) --> 3a + 12b = 36
3/x + 1/y = 14 --> 3a + b = 14 (x1) --> 3a + b = 14  _
                                                               11b = 22 --> b =2
3a + 2 = 14
3a = 12
a = 4
a = 4 --> 1/x = 4 --> x = 1/4
b = 2 --> 1/y = 2 --> y = 1/2

semoga membantu agan yusuf :D

Answer 2

Maybe :
1. x = 1/5 dan y = -1/3
2. x = 29 dan y = -1/4