Question 1129099
x, minutes for cold water faucet to fill tub
4x, minutes for hot water faucet to fill tub


{{{1/x+1/(4x)=1/3}}}

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{{{12x(1/x+1/(4x))=12(1/3)x}}}

{{{12+3=4x}}}

{{{15=4x}}}

{{{x=15/4}}}

{{{highlight(x=3&3/4)}}}




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check:
{{{1/(15/4)+1/(4(15/4))}}}

{{{4/15+1/15}}}

{{{5/15}}}

{{{1/3}}}