1. a) a-(b-c)= -17-(4+11)
=-17-15
=-32
b) -4-(-3+2)
=-4+1
=-3
2. a) -7-[-3-10+1)]+5
=-7-(-12)+5
=-7+12+5
=-7+17
=10
b) -[-31-26+14]-(-9)
=-(-57+14)+9
=-(-43)+9
=43+9
=52
3. -7+11+5= 4+5= 9
b) -4+(-10-2)
=-4-12
=-16
4. Cazul 1: Ambele pozitive
x+x-2=0
2x=2=>x=1
Cazul 2: Ambele negative
-x-(x-2)=0
-2x=-2
x=1
Cazul 3: prima poz a doua negativa
x-(x-2)=0
imposibil
Cazul 4: prima neg a doua poz
-x+x-2=0
imposibil
