-34-(-15)+(-7)-(-2)=-34+15-7+2=(15+2)-(34+7)=15+2=17=17-(34+7)=-(41-17)=-24
58+(-100)-(-12)=58-100+12=70-100=-30
45-(+4)-(+52)+(+3)=45-4-52+3=48-56=-8
-34-(-15)+(-7)-(-2)=-34+15-7+2=(15+2)-(34+7)=15+2=17=17-(34+7)=-(41-17)=-24
58+(-100)-(-12)=58-100+12=70-100=-30
45-(+4)-(+52)+(+3)=45-4-52+3=48-56=-8