What is teh slope equation of (4,-6) and m=3?

For all slope equations, their general form is always y=mx + c (always), where m is the gradient, in this case, it's 3.

Take y-coordinate and x - coordinate from (4,-6) and pluck it into the equation.

-6 = (3) (4) + c where c is unknown to us

-6 = 12 + c

c = - 18

so the slope equation is y=3x-18