What is 2/4 : 6/10 - 7/10 : 4/12

We must follow order of operations rules here, meaning that the indicated division must be performed before the indicated subtraction.

The first division shown above can be reduced to (1/2) (5/3), which comes to 5/6.

The second division can be reduced to (7/10) (3) = 21/10

Then we have the subtraction problem 5/6 - 21/10, or 25/30 - 63/30 = - 38/30 = - 19/15. This is the final answer.

2/4:6/10=5/6

7/10:4/12=21/10

21/10-5/6 = - 1 4/15 or - 19/15