Question 933669
the standard slope-intercept form for an equation of a line is 
{{{y = highlight_green(m)x + highlight(b)}}}  where m is the slope and b the y-intercept.  
.........
2x-6y=12
y = (1/3)x - 2 , m = (1/3)  (Green)
......
Line Perpendicular:  m = -3/1 (negative reciprocal) {{{(1/3)(-3/1) = -1}}} 
***Using point-slope form, {{{y - y[1] = highlight_green(m)(x - x[1])}}}P(-1,2)
y - 2 = -3(x+1)
y = -3x -1  (Blue)
{{{drawing(300,300,   -6, 6, -6, 6, grid(1), 
circle(0, -2,0.3),
circle(-1,2, 0.3),
circle(0,-1, 0.3),
graph( 300, 300, -6, 6, -6, 6,0, x/3 - 2, -3x-1) )}}}