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Y varies directly as x If x = 5 when y = 12. Write an equation that relates x and y. Then find x when y = 36

User Josephnvu
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1 Answer

13 votes
13 votes

\begin{gathered} y\text{ varies directly as x means that} \\ y=mx \\ \text{where m is a constant of proportionality.} \\ We\text{ know that when x=5, y =12, hence} \\ 12=m(5) \\ m=(12)/(5) \\ \text{Therefore, the euqtion searched is} \\ y=(12)/(5)x \\ \text{Now, we must find x when y=36. Then} \\ 36=(12)/(5)x \\ (36)/(12)=(x)/(5) \\ 3=(x)/(5) \\ 3\cdot5=x \\ x=15 \end{gathered}

User Ken Benoit
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