Which equation in point-slope form contains the points (2, 6) and (–1, 3)?

Using the formula for lines y=mx+b
To find out the gradient of the line, we do (y2-y1)/(x2-x1). 
(3-6)/(-1-2)= -3/-3= 1 is the slope of the line
So far, y=(1)x+b
Now substitute one of your given coordinates into this equation:
6=2+b
b=4
Therefore, the equation of the line is y=x+4

Hope i can you!

The coordinates of point a right now is (-3,-1) you have to multiply these coordinates by a factor of 2 to get (-6,-2)