Answer:
y=2x+3
Step-by-step explanation:
*Note: I am finding the equation in Slope Intercept form (y=mx+b; m= slope, b= y-int; (x,y)= a coordinate on the plane)
*Note: This is the Slope Intercept from: 
1. Find two points on the line: (3,9) and (0,3)
2. Using those points, find the slope (m):

m=2
3. Thankfully, we don't have to find the y-intercept because it is already shown in the graph.
b=3
4. Now plug in the unknowns into the equation:
y=2x+3
5. Enjoy your answer!!!!!!!!!!!!