# Math

Find the value of y for a given value of x, if y varies directly with x.

If y = –252 when x = 84, what is y when x = 74?

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1. y = kx
-252 = k(84)
k = -3

y(74) = -3(74) = -222

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2. Do the same thing with X 6, 18, 54, 162
Y 24, 72, 216, 640

2.52 = k(8.4)
K=0.03
Y(2.7)=0.03(2.7)=0.81

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3. f(x)=4x+7,find f(4)

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4. Find the value of x when y=24

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