Question

Suppose y varies directly as x. suppose also that y=34 when x=17. find y when x=56.

Answer 1

112

Explanation:

We can write the equation for the direct variation:

y = kx

34 = k(17)

34/17 = k = 2

Then for the new x-value:

y = 2(56) = 112

The value of y is 112 when x = 56.

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Or, we can write the relation as a proportion:

y/56 = 34/17

y = 56(34/17) = 112