Question 990997
Let {{{ d }}} = the distance in miles that your friend
travels until you catch up with your friend
{{{ d + 3 }}} = the distance in miles you cover until
you catch your friend
Let {{{ t }}} = time in hrs it takes to catch your friend
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Your friend's equation:
(1) {{{ d = 12t }}}
Your equation:
(2) {{{ d + 3 = 18t }}}
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Substitute (1) into (2)
(2) {{{ 12t + 3 = 18t }}}
(2) {{{ 6t = 3 }}}
(2) {{{ t = 1/2 }}}
You catch your friend in a 1/2 hr
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check:
(1) {{{ d = 12*(1/2) }}}
(1) {{{ d = 6 }}}
and
(2) {{{ d + 3 = 18*(1/2) }}}
(2) {{{ d = 9 - 3 }}}
(2) {{{ d = 6 }}}
OK