Diketahui 2x + 3y = - 8 X + 2y = -7 maka nilai x.y adalah

2x + 3y = -8
x + 2y = -7 dikalikan -2

2x + 3y = -8
-2x - 4y = 14 

-y = 6
y = -6
subs
x + 2y = -7
x + 2 (-6) = -7
x = -7 + 4
x = -3

jadi x.y = (-2).(-3) = 6

Sistem Persamaan Linear Dua Variabel.

2x + 3y = -8
x + 2y = -7 → x = -7 - 2y

2(-7 - 2y) + 3y = -8
-14 - y = -8 → y = -6
2x + 3(-6) = -8 → x = 5

xy = (5)(-6) = -30