Question 1156888
{{{ 50 - ( 3n + 5*2 ) }}} = change she received
{{{ 50 - 3n - 10 }}}
{{{ 40 - 3n }}}
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check:
Suppose {{{ n = 3 }}}
{{{ 40 - 3n = 40 - 9 }}}
{{{ 40 - 3n = 31 }}}
$31 change received
and
{{{ 50 - ( 3n + 5*2 ) }}}
{{{ 50 - ( 3*3 + 5*2 ) }}}
{{{ 50 - ( 9 + 10 ) }}}
{{{ 50 - 19 = 31 }}} 
$31 change received 
OK