Question 63235
food + ball + tax = total
1. {{{ f + b + .07b = 5.15 }}}
and
2. {{{ .07b = .18 }}}
solve for b
3. {{{ b = 2.57 }}} (rounded)
Plug 2 and 3 into 1
{{{ f + 2.57 + .18 = 5.15 }}}
combine like terms
{{{ f + 2.75 = 5.15 }}}
subtract 2.57 from both sides
{{{ f = 2.40 }}}


CHECK:
food + ball + tax = total
{{{ 2.40 + 2.57 + .18 = 5.15 }}}
{{{ 4.97 + .18 = 5.15 }}}
{{{ 5.15 = 5.15 }}}

YES!!!