Question 825929
Let {{{ t }}} = time in hours spent walking
Let {{{ d }}} = the distance that he walks in km
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Equation for walking:
(1) {{{ d = 3t }}}
Equation for Kalesa:
(2) {{{ d = 15*( 4 - t ) }}}
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By substitution:
(2) {{{ 3t = 15*( 4-t ) }}}
(2) {{{ 3t = 60 - 15t }}}
(2) {{{ 18t = 60 }}}
(2) {{{ t = 3.333 }}}
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(1) {{{ d = 3*3.333 }}}
(1) {{{ d = 10 }}} km
He walked 10 km
check:
(2) {{{ d = 15*( 4 - t ) }}}
(2) {{{ d = 15*( 4 - 3.333 ) }}}
(2) {{{ d = 15*.667 }}}
(2) {{{ d = 10 }}} km
OK