Question 876993
You can think of one cart as standing still
and the other car traveling at the sum
of their speeds
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Let {{{ s }}} = the speed of the slower car in mi/hr
{{{ s + 5 }}} = the speed of the faster car in mi/hr
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{{{ 393 = ( s + s + 5 )*3 }}}
{{{ 393 = ( 2s + 5 )*3 }}}
{{{ 393 = 6s + 15 }}}
{{{ 6s = 378 }}}
{{{ s = 63 }}}
{{{ s + 5 = 68 }}}
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Their speeds are 63 mi/hr and 68 mi/hr
check:
{{{ d[1] = s*t }}}
{{{ d[1] = 63*3 }}}
{{{ d[1] = 189 }}}
and
{{{ d[2] = 68*3 }}}
{{{ d[2] = 204 }}}
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{{{ d[1] + d[2] = 393 }}}
{{{ 189 + 204 = 393 }}}
{{{ 393 = 393 }}}
OK