Need help on writing a function rule for each table

Answer:
The first table is f(x) = 2x
Step-by-step explanation:
In order to solve the rest of these, follow these exact instructions. These steps will solve each problem. I'll use the first table as an example.
1. Pick two points in the chart.
(0, 0) (1, 2)
2. Use the slope formula to find slope.
m = (y1 - y2)/(x1 - x2)
m = (2 - 0)/(1 - 0)
m = 2/1
m = 2
3. Now that we have the slope, use that and a point to find the intercept in slope intercept form.
y = mx + b
2 = 2(1) + b
2 = 2 + b
0 = b
4. Now that you have the slope and intercept, put them into the equation for the model.
y = mx + b
y = 2x + 0
y = 2x