Question 1096754: Determine whether y varies directly with x. If so, find constant of variation and write the function rule.
a) x=-6, y= -2, x=9, y=3, x=21, y=7
b) Determine whether y varies directly with x. If so, find the constant variation. y+2=x
c) Y varies directly with x. If y=-14, when x=-7, find x, when y=22
Answer by Boreal(15235)   (Show Source):
You can put this solution on YOUR website! y=kx
then -2=k*-6
k=1/3; y=1/3 x
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3=k*9
k=1/3; y=1/3 x
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7=k*21
k=7/21=1/3, y=1/3 x
Y varies with x and the rule is y=1/3 x
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rewrite as y=x-2. y varies with x and the constant k = 1
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y=kx
-14=k(-7)
k=2
22=2*x
x=11
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