Answer:
2y = x + 2
Step-by-step explanation:
Looking at the graph, we can see from one point to the next (from right to left), the x-value rises by 2 and the y-value by 1;
From this we can work out the gradient between two points using the formula, i.e. the change/difference in y divided by the change/difference in x:

Joining the points gives a straight line, which means a constant gradient of ¹/₂
Use the line equation formula to get the function:
y - y₁ = m(x - x₁)
m = ¹/₂
x₁ = 0
y₁ = 1
y - 1 = ¹/₂.(x - 0)
y - 1 = ¹/₂.x
2y - 2 = x
2y = x + 2
Y = -3x + 6
y - 6 = -3x
-1/3 y + 2 = x
z = x -3
z = -1/3 y + 2 -3 = -1/3 y - 1
set z = 0
-1/3 y = 1
y = -3
set y = 0
z = - 1