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4 years ago

Assume that r varies directly with s. If r = 21 when s = 6, find r when s = 12.

1 answer:

6 0

$\bf \qquad \qquad \textit{direct proportional variation}\\\\
\textit{\underline{y} varies directly with \underline{x}}\qquad \qquad y=kx\impliedby 
\begin{array}{llll}
k=constant\ of\\
\qquad variation
\end{array}\\\\
-------------------------------$

$\bf r=ks\qquad \textit{we also know that }
\begin{cases}
r=21\\
s=6
\end{cases}\implies 21=k6\implies \cfrac{21}{6}=k
\\\\\\
\cfrac{7}{2}=k\qquad therefore\qquad \boxed{r=\cfrac{7}{2}s}
\\\\\\
\textit{if s = 12, what is \underline{r}?}\qquad r=\cfrac{7}{2}\cdot 12$

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3 years ago

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3 years ago

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3 years ago

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Ksenya-84 [330]

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4 years ago

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ANSWER: The width of the box is 10 inches; its length is 22 inches, and its height is 7 inches.

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4 years ago