Răspuns:
1)a+a+1+a+2+a+3+a+4=55
5a+10=55
5a=55-10
5a=45
a=45:5
a=9
a+1=9+1=10
a+2=9+2=11
a+3=9+3=12
a+4=9+4=13
9+10+11+12+13=55
2)
a+b+c=9848
a+b=7520
b+c=6694
7520+c=9848
c=9848-7520
c=2328
a+6694=9848
a=9848-6694
a=3154
b+2328=6694
b=6694-2328
b=4366
verificare:3154+4366+2328
7520+2328=9848
Explicație pas cu pas: