Question 884342
Let {{{ d }}} = miles traveled
Let {{{ t }}} = time traveling at 60 mi/hr
At 60 mi/hr:
(1) {{{ d = 60t }}}
(2) {{{ d = 50*( t + .2 ) }}}
----------------------
Substitute (1) into (2)
(2) {{{ 60t = 50*( t + .2 ) }}}
(2) {{{ 60t = 50t + 10 }}}
(2) {{{ 10t = 10 }}}
(2) {{{ t = 1 }}}
-------------
(1) {{{ d = 60t }}}
(1) {{{ d = 60*1 }}}
(1) {{{ d = 60 }}}
---------------
They traveled 60 mi
check:
(2) {{{ 60t = 50*( t + .2 ) }}}
(2) {{{ 60*1 = 50*( 1 + .2 ) }}}
(2) {{{ 60 = 50*1.2 }}}
(2) {{{ 60 = 60 }}}
OK