5 3/10 - 2 4/5

how do you do this kind of math

Answer: find a common denominator and make them into improper fractions.

Step-by-step explanation:

first find a common denominator in this case 10 so 5 3/10 would stay the same and 2 4/5 would become 2 8/10 now turn them to improper fractions so 5 3/10 5 times 10, 50 plus 3, 53/10 and do the same to 2 8/10 getting 28/10 no subtract straight across the top 53 - 28, 25 and put that over 10 25/10 now turn it back into a mixed number, 25 goes into 10 2 times with 5 leftover, 2 5/10 simplify 5/10 is the same as 1/2 final answer 2 1/2

2 1/2

Step-by-step explanation:

Since you cant do 3/10 - 4/5 you have to change the 5 in 4/5 to a 10 and you do that by multiplying by 2, so 4/5 * 2 = 8/10. Now the equation is 5 3/10 - 2 8/10, but you cant do 3 - 8 without getting a negative number, so you take 1 whole from the 5 in the first mixed number and add it to the 3/10. Since 10/10 is 1 whole and you have to add a whole, add the whole plus 3 so it would be 13/10. Now you can do 5 13/10 - 2 8/5 and you get 2 5/10, which gets simplified to 2 1/2.