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12 votes
If there is direct variation and y = 27 when x = 4, find y when x =12.

A. 9
B. 81
C. 1.78
D. 0.56

1 Answer

10 votes

Answer:

B

Explanation:

Given y and x vary directly then the equation relating them is

y = kx ← k is the constant of variation

To find k use the condition y = 27 when x = 4 , then

27 = 4k ( divide both sides by 4 )


(27)/(4) = 6.75 = k

y = 6.75x ← equation of variation

When x = 12 , then

y = 6.75 × 12 = 81

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