You can put this solution on YOUR website! To find the gradient it's y/x which in this case is (4/5)/3.
(4/5)/3 = -4/15 <===in this case, it slopes downwards meaning there has to be a negative sign in front of 4/15.
Use the point gradient formula: y-y1=m(x-x1) where y1 is -4/5, x1 is 3 and m is the gradient 4/15
y-4/5=-4/15(x-3)<===multiply both sides by 15.
15(y-4/5)=5(-4/5)(x-3)
15y-12=-4(x-3)
15y-12=-4x+12
general form: 4x+15y-24=0 gradient intercept form: y=(-4/15)x+8/5