102 - 30 = 72
Here are two ways to find that out for yourself. One way is to write the 30 under the 102, with the 3 lined up with the 10 and the 0 lined up with the 2. Then when you take away 3 from ten you get 7, the first digit of the answer, and when you take away 0 from 2 you get 2, the second digt of the answer.
Another way to do the problem is to think of 102 as one dollar and two cents. When you take away 30 cents from one dollar, you have 70 cents in change, and you still have the two cents, so you have 72 cents. A dollar and two cents minus 30 cents equals 72 cents.
102 - 16 = 86
12x12=144...144-42=102. 102 is the answer. Or, is the question meaning 12-42, which equals -30. Then, it would be 12x-30=-360. So, it's either 102 or -360. One of those two must be right.
115 - 102 + (3 x 5) = 30
42
30 102
3 2/5 - 7 1/6 = 3 12/30 - 7 5/30 = 102/30 - 215/30 = -113/30 = -3 23/30
-30 - (-24) = -30 + 24 = -6
137 - 35 = 102
-68
180 degrees minus 102 degrees equals 78 degrees.
1010 - 102 = 910
170 - (40%) = 102