Explicație pas cu pas:
Exercițiul 1:
a) (a+b)-c+(a+c)=(-2+3)-(-7)+[-2+(-7)]=1+7+(-9)=8-9=-1
b) (a-b)+(a-c)+(b-c)=(-2-3)+[-2-(-7)]+[3-(-7)]=-5+(-2+7)+(3+7)=-5+5+10=10
c) (a-b)+c-(a+c)=(-2-3)+(-7)-[-2+(-7)]=-5-7-(-2-7)=-12-(-9)=-12+9=-3
d) [(a-c)-b]-a={[-2-(-7)]-3}-(-2)=[(-2+7)-3]+2=(5-3)+2=2+2=4
Exercițiul 2:
a) -9+|-4|+7=-9+4+7=-5+7=2
b) |+7|-(-3)+|-1|=7+3+1=11
c) |-3+2|+(-10)=|-1|-10=1-10=-9
d) -17+|-3-5+2|+(-11)=-17+|-8+2|-11=-17+|-6|-11=-17+6-11=-11-11=-22