Question 156872
The statement " y varies directly as x" translates to {{{y=kx}}}



{{{y=kx}}} Start with the given equation



{{{12=k(3)}}} Plug in {{{y=12}}} and {{{x=3}}}



{{{4=k}}} Divide both sides by 3 to isolate "k"



So the variation constant is {{{k=4}}} which means that the equation is {{{y=4x}}}