If y varies directly with x, and if y = 10 when x = 2, how do you find the direct variation equation?

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Answer 1 · 2016-06-22T11:21:48

Variation Eqn. is $y = 5 x .$ $y=5x.$

We know that $y \propto x .$ $y prop x.$

$:. y=kx............(1),$ where $k$ is the constant of variation & $k!=0.$

Now to determine $k$ , we use the given cond. that when $x=2, y=10$ . Let us submit these resp. values in (1) to get, $10=2k,$ or, $k=5.$

Letting $k=5$ in (1), we get the Variation Eqn. as $y=5x.$

Answer 2 · 2016-06-22T11:25:25

The direct variation equation is $y=5x$

$y prop x :. y = k*x ; y=10;$ when $x=2 :. 10= k *2 or k =5$ (k is constant of variation). Hence the variation equation is $y=5x$ [Ans]