Question

biết a/a'+b'/b=1

      b/b'+c'/c=1

chứng minh rằng a.b.c+a'.b'.c'=0

Answer 1

\(\frac{a}{a'}+\frac{b'}{b}=1\)=> \(\frac{a}{a'}.\frac{b}{b'}+\frac{b'}{b}.\frac{b}{b'}=\frac{b}{b'}\)=> \(\frac{ab}{a'b'}+1=\frac{b}{b'}=1-\frac{c'}{c}\)

=> \(\frac{ab}{a'b'}=-\frac{c'}{c}\)=> abc = - a'b'c' => abc + a'b'c' = 0

Answer 2

chua hoc phan nay nen cug cha bt giai luon

Answer 3

a/a' + b'/b = 1 <=> ab + a'b' = a'b <=> abc + a'b'c = a'bc (1) (vì c # 0)
b/b' + c'/c = 1 <=> bc + b'c' = b'c <=> a'bc + a'b'c' = a'b'c (2) (vì a' # 0)
(1) + (2) => đpcm

Answer 4

Ko bt đúng hay sai nữa:VVVV>>>>

Answer 5

\(\sqrt[b]{b}b\)

Answer 6

tại sao a/a'xb/b'+b'/bxb/b' =b/b'