Question 326609
Let A (Adrianna) and B (Brooke) be their walking rates.
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Rate*Time=Distance
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{{{B=A-2}}}
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{{{B*T=12}}}
{{{T=12/B}}}
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{{{A*T=18}}}
{{{T=18/A}}}
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{{{12/B=18/A}}}
{{{18B=12A}}}
{{{B=(2/3)A}}}
Substitute into the first equation,
{{{(2/3)A=A-2}}}
{{{2A=3A-6}}}
{{{highlight(A=6)}}}kph
Then,
{{{B=(2/3)(6)}}}
{{{highlight(B=4)}}}kph