Question 1087621
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The length of rectangular box with a fixed height varies directly as the volume and
inversely as the width. If the length is 15 cm when the volume is l260cm^3 and the width is 8 cm,
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L, length
k, variation constant
w, width
v, volume


{{{L=kv/w}}}

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{{{Lw/v=k}}}

{{{k=15*8/1260}}}

{{{k=120/1260}}}

{{{k=2*2*3/(2*7*3*3)}}}

{{{k=2/21}}}

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{{{highlight(L=(2/21)v/w)}}}


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find the length when the volume is 840+cm%5E3 and the width is 5 cm.
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Just substitute the values and evaluate L.