數學高手先好入 一定要有十足把握

x=-7
and your question is wrong.

Q:

[( x ＋ 7 ) / ( x ＋ 6 )] ＋ [( x ＋ 9 ) / ( x ＋ 8 )] ＝ [( x ＋ 10 ) / ( x ＋ 9 )] ＋ [( x ＋ 6 ) / ( x ＋ 5 )]

Sol:

[( x ＋ 7 ) / ( x ＋ 6 )] ＋ [( x ＋ 9 ) / ( x ＋ 8 )] ＝ [( x ＋ 10 ) / ( x ＋ 9 )] ＋ [( x ＋ 6 ) / ( x ＋ 5 )]

1 ＋ 1 / ( x ＋ 6 ) ＋ 1 ＋ 1 / ( x ＋ 8 ) ＝ 1 ＋ 1 / ( x ＋ 9 ) ＋ 1 ＋ 1 / ( x ＋ 5 )

1 / ( x ＋ 6 ) + 1 / ( x ＋ 8 ) ＝ 1 / ( x ＋ 9 ) ＋ 1 / ( x ＋ 5 )

1 / ( x ＋ 8 ) － 1 / ( x ＋ 9 ) ＝ 1 / ( x ＋ 5 ) － 1 / ( x ＋ 6 )

1 / ( x^2 ＋ 17x ＋ 72 ) ＝ 1 / ( x^2 ＋ 11x ＋ 30 )

x^2 ＋ 11x ＋ 30 ＝ x^2 ＋ 17x ＋ 72

6x ＝ - 42

x ＝ - 7

Ans: x ＝ - 7