Cześć ;-)
Obliczenia
[tex]49^2=(50-1)^2=50^2-2\cdot50\cdot1+1^2=2500-100+1=\boxed{2401}\\\\51^2=(5+1)^2=50^2+2\cdot50\cdot1+1^2=2500+100+1=\boxed{2601}\\\\82^2=(80+2)^2=80^2+2\cdot80\cdot2+2^2=6400+320+4=\boxed{6724}\\\\39^2=(40-1)^2=40^2-2\cdot40\cdot1+1^2=1600-80+1=\boxed{1521}[/tex]
Wykorzystane wzory
[tex](a+b)^2=a^2+2ab+b^2\\\\(a-b)^2=a^2-2ab+b^2[/tex]
Pozdrawiam!