Question 1042463
Let {{{ t }}} = time in hrs for both of them
Let {{{ s }}} = Jason's speed in km/hr
{{{ s + 30 }}} = Brandy's speed in km/hr
Jason's equation:
(1) {{{ 250 = s*t }}}
Brandy's equation:
(2) {{{ 400 = ( s + 30 )*t }}}
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(1) {{{ t = 250/s }}}
Substitute (1) into (2)
(2) {{{ 400 = ( s + 30 )*( 250/s ) }}}
(2) {{{ 400s = 250s + 7500 }}}
(2) {{{ 150s = 7500 }}}
(2) {{{ 15s = 750 }}}
(2) {{{ s = 50 }}}
and
{{{ s + 30 = 80 }}}
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Brandy's speed was 80 km/hr
Jason's speed was 50 km/hr
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check:
(1) {{{ t = 250/s }}}
(1) {{{ t = 250/50 }}}
(1) {{{ t = 5 }}} hrs
and
(2) {{{ 400 = ( s + 30 )*t }}}
(2) {{{ 400 = ( 50 + 30 )*t }}}
(2) {{{ 400 = 80t }}}
(2) {{{ t = 400/80 }}}
(2) {{{ t = 5 }}} hrs
OK