Question 107078
you use your point-gradient formula again
y-y1=m(x-x1)

where m=-3 and x1,y1 is your point (4,2)
(x1=4,y1=2)

subbing into the equation
y-2=-3(x-4)

expand
y-2=-3x+12
y+3x-2-12=0
y+3x-14=0