Question 1189162
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Direct variation means the relationship can be written as a formula in the form<br>
{{{y=kx}}}<br>
We are told that 8 molecules of hydrogen and 4 molecules of oxygen make 4 molecules of water.  Using x for the number of molecules of oxygen and y for the number of molecules of hydrogen, that given information tells us<br>
{{{8=k(4)}}}
{{{k=8/4=2}}}<br>
So the direct variation equation is<br>
{{{y=2x}}}<br>
Then, if 32 molecules of oxygen (x) are used, the number of molecules of hydrogen required is y = 2(32) = 64.<br>