Question 342874
Rate*Time=Distance
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{{{R[1]*t=D[1]}}}
{{{R[2]*t=D[2]}}}
{{{R[2]=R[1]-20}}}
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Find {{{D}}} when {{{t=3}}},
{{{D=D[1]+D[2]}}}
{{{D=R[1]t+(R[1]-20)t}}}
{{{R[1](3)+(R[1]-20)(3)=270}}}
{{{2R[1]-20=90}}}
{{{2R[1]=110}}}
{{{highlight(R[1]=55)}}} mph
Then 
{{{R[2]=55-20}}}
{{{highlight(R[2]=35)}}} mph