1. y(8) = 3 - 4*8 = 3-32= -29
y(-5)= 3 - 4*(-5) = 3 +20 = 23
y(1) = 3 - 4*1 = 3-4 = -1
2. y=15
3-4x=15
3-15=4x
4x=-12
x=-3
y=-7
3-4x = -7
3+7 = 4x
10=4x
x=2.5
y=3.5
3-4x = 3.5
3-3.5 = 4x
4x = -0.5
x=-0.125
3. A(0;-1)
x=0
y(0)=3 - 4*0 = 3 # -1 Не принадлежит
B(-2;-5)
x=-2
y(-2) = 3-4*(-2) = 3 + 8 = 11 #-5 Не принадлежит
C(5;-17)
x=5
y(5)=3 - 4*5 = 3-20 = 17 Принадлежит!!!!!