Direct Variation
Question
y varies directly as x when x = 2, y = 14. What is y when x = 10?
Answer
In the given variation, y = 70 when x = 10.
Solution
[tex]\begin{array}{l} \rm Solving \ for \ the \ constant \ of \ variation, \\ \\ \rm y = kx \\ \\ \rm 14 = 2k \\ \\ \rm \dfrac{14}{2} = k \\ \\ \rm \bold{k = 7} \\ \\ \\ \rm Solving \ for \ y \ when \ x = 10, \\ \\ \rm y = kx \\ \\ \rm y = (7)(10) \\ \\ \rm \boxed{ \bold{y = 70}} \end{array}[/tex]
x.x
