Question 562303
Let {{{t}}} = number of minutes for the run
{{{ 6 - t }}} = number of minutes for the walk
Let {{{ d }}} = length of course in meters
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Equation for run:
{{{ d = 400t }}}
Equation for walk:
{{{ d = 80*( 6 - t ) }}}
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By substitution:
{{{ 400t = 80*( 6 - t ) }}}
{{{ 400t = 480 - 80t }}}
{{{ 480t = 480 }}}
{{{ t = 1 }}} min
{{{ 6- t = 6 - 1 }}}
{{{ 6 - t = 5 }}} min
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{{{ d = 400t }}}
{{{ d = 400*1 }}}
{{{ d = 400 }}}
check:
{{{ d = 80*( 6 - t ) }}}
{{{ d = 80*5 }}}
{{{ d = 400 }}}
The length of the course was 400 m