18 + 2 + 10 = 30
18/10
2 + 6 + 8 + 10 + 12 + 14 + 16 + 18 + 20 = 106
-18
18 + 10 + 28 + 10 = 66
few errors in your title: 2 plus 4 = 6 6 plus 9 = 15 10 plus 25 = 35 18 + 81 = 99
2
There is no need to simplify this, it is only a sum. 21 + (10/2) - 18 = 8
5*4=20 20/2=10 10+8=18 18
It is: 1/2+10/18 = 19/18
18 + 6 + 2 = 26
18 + 10 = 28
-8 minus 10 -8 plus 10