Răspuns :
a+a+1+a+2+a+3=42
4a+6=42
4a=42-6
4a=36
a=36:4
a=9(I nr)
9+1=10(II nr)
9+2=11(III nr)
9+3=12(IVnr)
4a+6=42
4a=42-6
4a=36
a=36:4
a=9(I nr)
9+1=10(II nr)
9+2=11(III nr)
9+3=12(IVnr)