Question 21936
30% of their monthly income is food and food costs $645.00.
Let m = monthly income.

{{{(30/100) * m = 645.00}}}
next, multiply both sides by 100/30
{{{ m = (100/30) * 645.00 }}}
solve the right side
{{{ m = 2150 }}}
check: is 30% of this 645.00?
{{{ (30/100) * 2150 = 645 }}}
it checks
monthly income = $2150.00