When we say that y varies <em>directly </em>with x, we mean that whatever value x is scaled up by, y will be scaled up by, too. The simplest kind of direct variation is one where y = x for all values of x. If you multiply x by some value, y must be multiplied by that same value.
More generally, though, you'll have something of the form y = kx, where the variable k here is referred to as the <em /><em>constant of proportionality.</em> Another way you can think of k is as the <em>ratio of y to x</em>.
In this problem, you're given a set of values for x and y, and you'll need to use those to find the constant of proportionality before you set up an equation relating x to y. Substituting our general equation y = kx for the given values, we have:
-5 = k(15)
To get k, simply divide both sides by 15 to obtain:
k = -5/15 = -1/3
So, our general equation, for <em>any x</em>, would be y = (-1/3)x
Answer:
36oz of laundry for $10
Hope This Helps! Have A Nice Day!!
Answer:
486
Step-by-step explanation:
9(9) added 6 times
Answer:
18
Step-by-step explanation:
multiply then add a all together
Answer: -9
Step-by-step explanation: 2 + 7 = 9 and just put an negative in front of 9
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-9 -_-</h2>