Question 994497
Let {{{ d }}} = distance in miles you travel
until you catch friend
Let {{{ t }}} = time in hours it takes you
to catch friend
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Friend's equation:
(1) {{{ d - 3 = 12t }}}
Your equation:
(2) {{{ d = 18t }}}
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Substitute (2) into (1)
(1) {{{ 18t - 3 = 12t }}}
(1) {{{ 6t = 3 }}}
(1) {{{ t = 1/2 }}}
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You will catch friend in 1/2 hr
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check:
(2) {{{ d = 18*(1/2) }}}
(2) {{{ d = 9 }}}
and
(1) {{{ d - 3 = 12*(1/2) }}}
(1) {{{ d - 3 = 6 }}}
(1) {{{ d = 9 }}}
OK