Question 745124
Let {{{ d }}} = the distance to work
Let {{{ s }}} = the speed of the bus
Convert minutes to hours
By car:
(1) {{{ d = ( s + 12 )*(1/2) }}}
By bus:
(2) {{{ d = s*(3/4) }}}
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Substitute (2) into (1)
(1) {{{ s*(3/4) = ( s + 12 )*(1/2) }}}
Multiply both sides by {{{ 4 }}}
(1) {{{ 3s = 2*( s + 12 ) }}}
(1) {{{ 3s = 2s + 24 }}}
(1) {{{ s = 24 }}}
Substitute this result into (2) 
(2) {{{ d = 24*(3/4) }}}
(2) {{{ d = 6*3 }}}
(2) {{{ d = 18 }}}
The distance to work is 18 miles