Răspuns:
a. 4-5+7-9+11=
-1+7-9+11
6-9+11
-3+11
=8
b. -5-[-8+(-4)]-(-7)=
-5-(-8+4)+7
-5-(-4) +7
-5+4+7
-1+7
=6
a=1+3-5+7-9+11
a=4-5+7-9+11
a= -1+7-9+11
a=6-9+11
a= -3+11
a=8
|a|=|8|=8
b= -5-[-8+(-4)]-(-7)
b= -5-(-12)-(-7)
b=7-(-7)
b=14
|b|=|14|=14
