Question 496417
Equation for the one going 42 mi/hr
(1) {{{ d = 42t }}}
Equation for the other car
(2) {{{ d + 82.5 = 53t }}}
(2) {{{ d = 53t - 82.5 }}}
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Since {{{d}}} is the same in both,
{{{ 42t = 53t - 82.5 }}}
{{{ 11t = 82.5 }}}
{{{ t = 7.5 }}}
They will be 82.5 mi apart in 7.5 hrs