a)
$\phantom{X}\dbinom{12}{0}\,+\,\dbinom{12}{1}\,+\,\dbinom{12}{2}\,+\;...\;+\,\dbinom{12}{12}\,=\phantom{X}$
b)
$\phantom{X}\dbinom{2}{2}\,+\,\dbinom{3}{2}\,+\,\dbinom{4}{2}\,+\,\dbinom{5}{2}\,+\,\dbinom{6}{2}\,+\,\dbinom{7}{2}\,=\,$
c)
$\phantom{X}\dbinom{2}{0}\,+\,\dbinom{3}{1}\,+\,\dbinom{4}{2}\,+\,\dbinom{5}{3}\,+\,\dbinom{6}{4}\,+\,\dbinom{7}{5}\,=\phantom{X}$
d)
$\phantom{X}\dbinom{5}{0}\,+\,\dbinom{6}{1}\,+\,\dbinom{7}{2}\,+\,\dbinom{8}{3}\,=\phantom{X}$
