tolong banget no 2 sama 3 aja.... besok dikumpulkan...

No 2.
Mencari Y :
5x + 8y = 100 (Dikali 8) Jadi: 40x + 64y = 800
8x - 5y = 71 (Dikali 5) Jadi: 40x - 25y = 355
Hasil (Jadi:) dikurangin.
89y = 445
y = 445/89
y = 5

Mencari X :
5x + 8y = 100
5x + 8 (5) = 100
5x + 40 = 100
5x = 100 - 40
5x = 60
x = 60/5
x = 12

Soal: Y - X = 5 - 12 = -7