To draw a straight line we need only two points.
f(x) = x
for x = 0 → y= 0→ (0; 0)
for x = 2 → y = 2 → (2; 2)
g(x) = (x + 2) - 3
for x = 0 → y = (0 + 2) - 3 = 2 - 3 = -1 → (0; -1)
for x = -2 → y = (-2 + 2) - 3 = 0 - 3 = -3 → (-2; -3)
h(x) = 2(x - 1)
for x = 0 → y = 2 · (0 - 1) = 2 · (-1) = -2 → (0; -2)
for x = 1 → y = 2· (1 - 1) = 2 · 0 = 0 → (1; 0)
d(x) = 1/2 x + 2
for x = 0 → y = 1/2 · 0 + 2 = 0 + 2 = 2 → (0; 2)
for x = -4 → y = 1/2 · (-4) + 2 = -2 + 2 = 0 → (-4; 0)
Look at the picture.