<p>Could someone please explain what directly proportional and inversely proportional mean? And how to use them?</p>
<p>BB says inversely proportional is y=xk … i then used that to see what the right answer for something was, but i just put the numbers in the equation</p>
<p>If taxes are raised on gasoline, cigarettes or beer, the total cost goes up (directly proportional), but the driving/smoking/drinking goes in the opposite way, down (inversely proportional). </p>
<p>The use goes down bcos people can’t afford as much, so they buy less.</p>
<p>Directly - y=kx (k is a constant, obviously)
Inverse - y=k/x (k is a constant)</p>
<p>For direct proportions, if y goes up, x goes up. For inverse, if y goes up, x goes down</p>