Respuesta :
[tex] \bf _nC_r=\cfrac{n!}{r!(n-r)!}\qquad \qquad \qquad \qquad \qquad _7C_3=\cfrac{7!}{3!(7-3)!}
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\textit{use the }[!]\textit{ factorial button or the }[_nC_r]\textit{ button in your calculator} [/tex]
[tex] \bf _nC_r=\cfrac{n!}{r!(n-r)!}\qquad \qquad \qquad \qquad \qquad _7C_3=\cfrac{7!}{3!(7-3)!}
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\textit{use the }[!]\textit{ factorial button or the }[_nC_r]\textit{ button in your calculator} [/tex]
