Suppose that y varies directly with x and y=3 when x=9. what is y when x=18?
its 6
To find the value of y when x=18, we can use the direct variation equation. The direct variation equation is given by:
y = kx
where k is the constant of variation.
We are given that y=3 when x=9. Substituting these values into the direct variation equation, we get:
3 = k * 9
Solving this equation for k, we divide both sides by 9:
k = 3/9
k = 1/3
Now that we know the constant of variation is 1/3, we can find the value of y when x=18 by substituting x=18 into the direct variation equation:
y = (1/3) * 18
y = 6
Therefore, when x=18, y=6.
To find the value of y when x=18, we can use the concept of direct variation. In direct variation, if one variable (y) varies directly with another variable (x), it means they have a constant ratio between them. This can be represented by the equation y = kx, where k is the constant of variation.
In this case, we are given that y varies directly with x, so we can write the equation as y = kx. We are also given that when x=9, y=3. We can use this information to find the value of k.
Substituting the given values into the equation, we have:
3 = k * 9
To find the value of k, divide both sides of the equation by 9:
k = 3/9 = 1/3
Now that we know the value of k, we can use it in the equation y = kx to find the value of y when x=18:
y = (1/3) * 18
y = 6
Therefore, when x=18, y equals 6.
y/x = 3/9 = 1/3.
y/18 = 1/3.
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