Question

解13/(x-4)-10/(x-3)=4/(x-5)-1/(x-1) 1/(x+1)+1/(x+7)=1/(x+5)+1

Answer 1

13/(x-4)-10/(x-3)=4/(x-5)-1/(x-1)

左右两边分别通分得

（3x+1)/(x-4)(x-3)=(3x+1)/(x-5)(x-1)

∴3x+1=0或(x-4)(x-3)=(x-5)(x-1)

∴x=-1/3或x=7

1/(x+1)+1/(x+7)=1/(x+5)+1/(x+3)

2(x+4)/(x²+8x+7)=2(x+4)/(x²+8x+8)

x+4=0或x²+8x+7=x²+8x+8(无义)

x=-4