Bonjour,
+(+) => +
+(-) => -
-(-) => +
-(+)=> -
-35-3x11 =
-35 -33 =-68
-18+(-35) =
-18 -35 = -53
-52-(-10) =
-52+10 = -42
3+4x6-6x9 =
3+24-54 = -27
1-(-8+5x9) =
1-( -8 +45)
= 1- (37)
= 1+37 = 38
-15-60+5x12 =
-75 + 60 = -15
25-(-32)-2 =
25+32 -2 = 55
-13+15 = 2
4x25-20x5 =
100 - 100 =0