急!! 數學題1題

ma - m n - nx
----------- x ----------
xb - bac - c

m(a - 1)n(1 - x)
= ------------ x ------------
b(x - 1) c(a - 1)

m- n
= ----- x----
bc

mn
= -----
bc

mn/bc

[ (ma - m) / (xb - b) ] * [ (n - nx) / (ac - c) ]
= [ ma - m) * n - nx) ] / [ xb - b) * ac - c) ]
= [ m(a - 1) * n(1 - x) ] / [ b(x - 1) * c(a - 1) ]
= [ mn(a - 1)(1 - x) ] / [ bc(x - 1)(a - 1) ]
= [ -mn(a - 1)(x - 1) ] / [ bc(a - 1)(x - 1) ]
= -mn/bc

_mn__
= -- bc

ma - m n - nx
----------- X ----------
xb - bac - c

m (a - 1)n(1 - x)
= ------------ X ------------
b(x - 1) c(a - 1)

m n
= ----- X (- ----)
b c

m X n
= ------------
b X c
mn
= - -----
bc

2007-01-09 17:23:57 補充：
The answer is: = -mn/bc

ma-m n-nx
------ x --------
xb-b ac-c

=m(a-1) n(1-x)
------ x --------
b(x-1) c(a-1)

= m n(1-x)
-------x-----------
b(x-1) c

= m -n
------x-------
b c

= mn
- -----
bc

= (ma-m)(n-nx)/(xb-b)(ac-c)
= [m(a-1)][n(1-x)]/[b(x-1)][c(a-1)]
= [m(a-1)][-n(x-1)]/[b(x-1)][c(a-1)] 約左
= -mn/bc