No 2 tolong gmn caranya

5/x + 4/y = 13 |1| 5/x + 4/y = 13
3/x - 2/y = 21 |2| 6/x - 4y = 42
------------------------------------------- +
............................ 11/x = 55 => x = 11/55 = 1/5
5/x + 4/y = 13
5/(1/5) + 4/y = 13
25 + 4/y = 13
4/y = -12
y = 4/-12 = -1/3

x - y = 1/5 - (-1/3) = (3 + 5)/15 = 8/15

Mapel : Matematika
Kelas : VII SMP
Bab : Aljabar

Pembahasan :
Terlampir...

X0 = 1/5 dan Y0 = -1/3
Maka...
X0 - Y0
= 1/5 - (-1/3)
= 1/5 + 1/3
= (5 + 3)/(5.3)
= 8/15