1/30 + 1/42 + 1/ 56 + 1/ 72 + 1/90 + 1/110 + 1/132 : x = 21/x

1 bình luận về “1/30 + 1/42 + 1/ 56 + 1/ 72 + 1/90 + 1/110 + 1/132 : x = 21/x”

1. 1/30 + 1/42 + 1/ 56 + 1/ 72 + 1/90 + 1/110 + 1/132 : x = 21/x

   <=>2/35+1/ 56 + 1/ 72 + 1/90 + 1/110 + 1/132 : x = 21/x

   <=>3/40+1/ 72 + 1/90 + 1/110 + 1/132 : x = 21/x

   <=>4/45+1/90 + 1/110 + 1/132 : x = 21/x

   <=>1/10+ 1/110 + 1/132 : x = 21/x

   <=>6/55+1/132 : x = 21/x

   <=>7/60:x=21/x

   <=>7/60xx1/x=21/x

   <=>7/60x=21/x

   <=>7x=60x xx 21

   <=>7x=1260x

   <=>7x-1260=0

   <=>-1253x=0

   <=>x=0/-1253

   <=>x=0

   Vậy x=0

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