Răspuns:
31^2=(30+1)^2=900+60+1=961
51^2=(50+1)^2=2500+100+1=2601
49^2=(40+9)^2=1600+18*40+81=1600+720+81=2401
99^2=(90+9)^2=8100+18*90+81=8100+1620+81=9801
26^2=(20+6)^2=400+12*20+36=400+240+36=676
101^2=(100+1)^2=10000+200+1=10201
Explicație pas cu pas: