Since we have been given two years with their populations, we actually have two points. The points are (6,35,200) and (11,43,700).
The first step to find the equation of the line is finding the slope. The slope formula says:
m = (y2 - y1)/(x2 - x1)
After substituting, we have
m = (43,700 - 35,200)/(11 - 6)
m = 8,500/5
m = 1,700
Now that we have the slope, we can use the point-slope formula to do this. I will use the first point, but you will get the same answer if you use the second point.
y - y1 = m(x - x1) Point-slope formula
y - 35,200 = 1,700(x - 6) Substitution
y - 35,200 = 1,700x - 10,200 Distribute the 1,700
y -35,200 + 35,200 = 1,700x - 10,200 + 35,200 Add 35,200 to each side
y = 1,700x + 25,000 Simplify