First, we need to calculate the slope
we need 2 points of the line
in this case, I will choose
P1(0,0)=(x1,y1)
P2(1,3)=(x2,y2)
the slope can be calculated with the next formula
[tex]m=\frac{y_2-y_1}{x_2-x_1}[/tex][tex]m=\frac{3-0}{1-0}=\frac{3}{1}=3[/tex]in order to calculate the equation we follow the next formula
[tex](y-y_1)=m(x-x_1)[/tex][tex](y-0)=3(x-0)[/tex]the equation is
[tex]y=3x[/tex]