Gina had 1/2 a liter of Dr. Pepper. She gave 2/5 of a liter to her friend. How much does she have left?

1/10

Step-by-step explanation:

1) find a common factor between the two denominators.

2 and 5 have a common factor of 10. you can find this by multiplying the denominators.

2) now that you have a common denominator of 10, you'll need to change the numerators too. you do this by finding out how many times the denominator goes into your common factor. 5 goes into 10 two times so you would multiply 2 x 2. two goes into 10 five times so multiply 5 x 1.

3) you now have both fractions that share a common factor. now you have to subtract them.

5/10 - 4/10 = 1/10