Решите систему уравнений способом сложения 2) x/6 + y/4 = 6 x/8 - y/2 = -1 4) x/12 + y/5 = 8 x/4 - y/7 = -2

2
x/6 + y/4 = 6⇒2x+3y=72
x/8 - y/2 = -1⇒x-4y=-8/*(-2)⇒-2x+8y=16
11y=88
y=8
2x+24=72
2x=48
x=24
(24;8)
4
x/12 + y/5 = 8⇒5x+12y=480
x/4 - y/7 = -2
⇒7x-4y=-56/*3⇒21x-12y=-168
26x=312
x=12
60+12y=480
12y=420
y=35
(12;35)