Answer :
[tex]M=\frac{y2-y1}{x2-x1}\text{ (1)}[/tex][tex]M=\frac{5-2}{3-(-9)}=\frac{3}{12}=\frac{1}{4}[/tex]
now we are going to find b
[tex]b=y-Mx[/tex]we are going replace (3,5) in the last equation
[tex]b=5-\frac{1}{4}\cdot3[/tex][tex]b=5-\frac{3}{4}=\frac{17}{4}[/tex]the equation is
[tex]y=\frac{1}{4}x+\frac{17}{4}[/tex]