Question 1014375
Let {{{ x }}} = the price of the meal BEFORE the tip was added
{{{ .2x = 7.5 }}}
{{{ x = 7.5/.2 }}}
{{{ x = 37.5 }}}
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The cost of the meal AFTER the tip is added is:
{{{ 37.5 + 7.5 = 45 }}}
$45
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The $9 you got is {{{ .2*45 = 9 }}}
This is taking 20% of the meal price PLUS the tip