Объяснение:
(y-y₁)/(y₂-y₁)=(x-x₁)/(x₂-x₁)
(y-1)/(2-1)+(x-2)/(-2-2)
y-1=(x-2)/(-4)
y=-x/4+1/2+1
y=-x/4+3/2
y=-0.25x+1.5
