Question 669859
Kate shelved {{{ x }}} books
Beth shelved {{{ x + 10 }}}
given:
{{{ 86 = x + x + 10 + ( x + 10 ) }}}
{{{ 86 = 3x + 20 }}}
{{{ 3x = 86 - 20 }}}
{{{ 3x = 66 }}}
{{{ x = 22 }}}
{{{ x + 10 = 32 }}}
Beth shelved 32 books