-8
原式化御隐亩简
(x+8)携禅/(x+7)-(x+7)/镇森(x+6)=(x+11)/(x+10)-(x+10)/(x+9)
(X+6)(X+7)=(X+9)(X+10)
13X+42=19X+90
X=-8
(x+8)/(x+7)+(x+10)/(x+9)=(x+7)/(x+6)+(x+11)/(x+10)
1 + [1/察核锋(x+7)] + 1 + [1/败晌(x+9)] = 1 + [1/(x+6)] + 1+ [1/(氏族x+10)]
[1/(x+7)] + [1/(x+9)] = [1/(x+6)] + [1/(x+10)]
[(x+7) + (x+9)]/[x^2+16x+63] = [(x+6) + (x+10)]/[x^2+16x+60]
2x+16=0
x=-8
化简整理档侍得:行扰吵李盯 1/(X+7)+1/(X+9)=1/(X+6)+1/(X+10)
(2X+16)/(X^2+16X+63)=(2X+16)/(X^2+16X+60)
则2X+16=0, X=-8.