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28 votes
Suppose that y varies directly with x and y=-9 when x=3. What is y when x=18

User Barakbd
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1 Answer

16 votes
16 votes

Answer:

y = - 54

Explanation:

Given that y varies directly with x then the equation relating them is

y = kx ← k is the constant of variation

To find k use the condition y = - 9 when x = 3 , then

- 9 = 3k ( divide both sides by 3 )

- 3 = k

y = - 3x ← equation of variation

When x = 18 , then

y = - 3 × 18 = - 54

User Onychomys
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