When we are having a point (x1,y1) and slope (m) then the equation of line is given by y - y1 = m (x - x1)
Here we do have following data provided they are;
Placing values in the given equation we get,
[tex]\implies\sf{y - y1 = m(x - x1)}[/tex]
[tex]\implies\sf{y - ( - 1) = - 3(x - 2)}[/tex]
[tex]\implies\sf{y + 1 = - 3(x - 2)}[/tex]
[tex]\implies\sf{y + 1 = - 3x + 6}[/tex]