Write an equation for the data values below:
{(2,3),(3,5),(4,7),(5,9)}
goes up two when it goes right one
goes up 6 when it goes right 3
so
The slope is always 2. We can use a simple straight line
y = m x + b where the slope:
m = 2
Now put a point in, like the first one
3 = 2 (2) + b
so
b = -1
so I claim
y = 2 x - 1