53/10 - 2 4/5
how do you do this kind of math

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.

the one on the bottom left

step-by-step explanation:

all of the other ones have a specific pattern

the least common denominator is 40