Question 953093
Let {{{ d }}} = distance he walks in km
{{{ 6 - d }}} = the distance he takes bus in km
Let {{{ t }}} = time in hrs he walks
{{{ .5 - t }}} = time in hrs he spends on bus
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Equation for walking:
(1) {{{ d = 5t }}}
Equation on bus:
(2) {{{ 6 - d = 40*( .5 - t ) }}}
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(2) {{{ 6 - d = 20 - 40t }}}
substitute (1) into (2)
(2) {{{ 6 - 5t = 20 - 40t }}}
(2) {{{ 35t = 14 }}}
(2) {{{ t = 14/35 }}}
(2) {{{ t = 2/5 }}}
and
(1) {{{ d = 5t }}}
(1) {{{ d = 5*(14/35) }}}
(1) {{{ d = 2 }}}
He walks 2 km
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check:
(2) {{{ 6 - d = 40*( .5 - t ) }}}
(2) {{{ 6 - 2 = 40*( .5 - .4 ) }}}
(2) {{{ 4 = 40*( .1 ) }}}
(2) {{{ 4 = 4 }}}
OK
(1) {{{ d = 5t }}}
(1) {{{ 2 = 5*(2/5) }}}
(1) {{{ 2 = 2 }}}
OK