Question 804040
Let {{{ a }}} = the 1st part of the trip
Let {{{ b }}} = the 2nd part of the trip
--------------
{{{ a + b = 1356 }}}
{{{ b = a - 284 }}}
----------------
By substitution:
{{{ a + a - 284 = 1356 }}}
{{{ 2a = 1356 + 284 }}}
{{{ 2a = 1640 }}}
{{{ a = 820 }}}
and, since
{{{ b = a - 284 }}}
{{{ b = 820 - 284 }}}
{{{ b = 536 }}}
The return trip was 536 miles
check:
{{{ a + b = 1356 }}}
{{{ 820 + 536  = 1356 }}}
{{{ 1356 = 1356 }}}
OK