Найдите точку пересечения прямых: y-3x=10 и x+y=2​

x=2-y

y-3(2-y)-10=0

y-6+3y-10=0

2y-16=0

2y=16

y=8

x=2-8=-6

(-6,8)

d(y)=r/{-3; 3} вот

i'm not sure that's right, but folowing my minds:

as k+k=t and t+t=k it means that t=k. so it doesn't matter what number to substitute for letters, and c=0. hope, i helped you=)