Himpunan dari sistem persamaan {5/x + 4/y =13 {3/x - 2/y = 21 Maka nilai dari 15 (x-y)=

gunakan metode eliminasi

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

10/x + 8/y = 26
12/x - 8/y = 84
___________+
22/x = 110
x110 = 22
x = 22/110
x = 11/55
x = 1/5

gunakan metode subtitusi
5/x + 4/y = 13
4/y = 13 - 5 / 1/5
4/y = 13 - 25
4/y = -12
-12y = 4
y = - 4/12 = - ⅓

maka
15(x-y)
15(1/5 - (-⅓)
15 ( 1/5 + 1/3
15(8/15) = 8
jawabannya 8

semoga berguna +_+