asssuming the original equation is f(x)=-3x
vertical stretch of 4 means multiply whole function by 4
move to right by 4 means minus 4 from every x
so first
f(x)=-3x
strech,
times 4
y=-12x
now move to right 4
minus 4 from every x
g(x)=-12(x-4)
g(x)=-12x+48
g(x)=-12(x-4) or -12x+48