Write the slope-intercept form of the equation of the line which passes through the points (1, 6) and (2, 9

Question

nurali · Answer

Start with the slope formula. 

$$m=\frac{ y_{2}-y_{1} }{ x_{2}-x_{1} }$$

Plug in y2=9, y1=6, x2=2 and x1=1

$$m=\frac{ 9-6 }{ 2-1 }$$

$$m=3$$

So the slope of the line that goes through the points  (1, 6) and (2, 9) is m=3

Now let's use the point slope formula: 

Start with the point slope formula 

$$y-y _{1}=m(x-x _{1})$$

Plug in m=3, x1=1 and y1=6

$$y-6=3(x-1)$$

$$y-6=3x-3$$

$$y=3x-3+6$$

$$y=3x+3$$