Please find attached photograph for your answer.
If she started with $40 and ended up with $10, that means she must've used $30. Since the popcorn bags were all identical and she bought 12, you can divide 30 by 12 which gives you 2.5.
The answer is $2.50.
Please try to follow this closely.
Ready ? OK, here goes:
<em> Add 2.6 to each side of the equation.</em>
It is undefined when the denominator is 0
