Iam doing mathematics right now and i need with a few of points walk me through the problem are the 1. 1/4 - 7/10 2. 2/3 - 1/2

For both of these you want to find a common factor
1. 10(1)-  4(7)       the easiest way to do this you multiply 4*10 for a common
    10(4)   4(10)     factor of 40. You multiply the same number on top and on
10 - 28 = -18        and on the bottom to keep the same value (whatever you do
40   40     40        on the bottom you do on the top). This let's you have the 
1. -18/40              same denominator so you can just subtract the numbers.

2. 2(2)- 3(1)
    2(3)  3(2)
     4  -  3 = 1
     6  -  6    6
2. 1/6