Question 713024
Faster car's equation:
(1) {{{ d = 45t }}}
Slower car's equation:
(2) {{{ d - 13 = 30t }}}
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Substitute (1) into (2)
(2) {{{ 45t - 13 = 30t }}}
(2) {{{ 15t = 13 }}}
(2) {{{ t = 13/15 }}} hrs
(2) {{{ t = (13/15)*60 = 52 }}} min
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check:
(1) {{{ d = 45*(13/15) }}}
(1) {{{ d = 39 }}} mi
and
(2) {{{ d - 13 = 30*(13/15) }}}
(2) {{{ d = 13 + 26 }}}
(2) {{{ d = 39 }}} mi
OK