Question

1215 (6) 1216 и 1217 пж помогите

Answer 1

№1215 (6)
$left { {{12x-y=18} atop {x+0.5y=5} right.$
$left { {{12x-y=18} atop {x+0.5y=5 | *2} right.$
12x - y + 2x + y = 18 + 10
14x = 28
x = 2
12x - y = 18
y = 12x - 18
y = 12*2 - 18
y = 24-18
y = 6

№1216