Question 300322
Set-Up
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Let T = time in hours
Let X = distance
Equation 1: {{{6*T = X}}} (Clarke family)
Equation 2: {{{14*T = X + 20}}} (Rourke family)
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Solution:
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Notice that equation 1 is already solved for X.  Now you can plug 6T into equation 2 for X.
Equation 2: {{{14*T = X + 20}}}
{{{14T = 6T + 20}}} Subtract 6T from both sides
{{{8T = 20}}} Divide both sides by 8
{{{highlight(T = 2.5)}}}