18 x 3 + 12 - 1 x 34 + 13 - 2 x 56 = 67
<=Work=>
18 x 3 = 54
1 x 34 = 34
2 x 56 = 112
(54) + 12 - (34) + 13 - (112)
66 - 34 + 13 - 112
32 + 13 - 112
45 - 112
= 67
-8+3+-8--3
minusing a negativ means adding a positive
adding a negaative means minusing a positive
-8+3-8+3
-5-8+3
-13+3
-10
