Question 823750
Let {{{ w }}} = miles walking
Let {{{ t[w] }}} = hours spent walking
{{{ 171 - w }}} = miles biking
{{{ 7 - t[w] }}} = hours spent biking
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Equation for biking:
(1) {{{ 171 - w = 30*( 7-t[w] ) }}}
Equation for walking:
(2) {{{ w = 4t[w] }}}
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Substitute (2) into (1)
(1) {{{ 171 - 4t[w] = 30*( 7-t[w] ) }}}
(1) {{{ 171 - 4t[w] = 210 - 30t[w] }}}
(1) {{{ 26t[w] =39 }}}
(1) {{{ t[w] = 1.5 }}} hrs
{{{ 7 - 1.5 = 5.5 }}}
5.5 hrs were spent on bicycle