y = kx, k being a constant
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Find k :
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When x = 12, y = 3
3 = k(12)
k = 3/12
k = 1/4
Equation : y = 1/4 x
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Find y when x = 20:
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When x = 20,
y = 1/4 (20)
y = 5
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Answer: y = 5
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