Direct variation is essentially a linear equation, where there is a constant rate. Direct variation can be applied to many things, and we can use it to represent how much money someone has in their bank account after "x" weeks if they're depositing a constant amount of money each week.

So a practical example would be: If someone just opened a bank account and deposits $50 every week, how many weeks will it take for them to have $400 in their account.

So the slope is given in the question, it's $50, since their depositing that constant amount each week. So this gives us the equation: $y=50x$ where x represents the amount of weeks. The y represents the amount of money they have, and since we want to find when this equals 400, we set the y=400, and then solve for x. This gives us the equation: $400=50x$ . Dividing both sides by 50 you get: $8=x$ . So it'll take 8 weeks to have $400 dollars, if you deposit 50 dollars each week.

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2 years ago