Sa se rezovle ecuatia C8 luate cate 5 – x = C7 luate cate 5 #combinatorialequations

Ecuatie cu elemente combinatorice
Sa se rezovle ecuatia C8 luate cate 5 – x = C7 luate cate 5
C8 luate cate 5 = combinari de 8 luate cate 5 ;
C7 luate cate 5 = combinari de 7 luate cate 5 ;
C8 luate cate 5 = 8!/5! * inmultit cu 8-5 tot! ;
C8 luate cate 5 =8!/5!*3! = 8x7x6/1x2x3=7*8 = 56 ;
C7 luate cate 5 =7!/5! * inmultit cu 7-5 tot! ;
C7 luate cate 5 =7!/5!*2! = 7x6/1x2=7*6 /2= 21
C8 luate cate 5 – x = C7 luate cate 5 ;
56 - x = 21 ; x = 56 -21= 35 ; x = 35 este solutia .