Put 1an−xanan+1=1an+yn;
then (an+yn)(an+1−x)=anan+1;
∴yn=anxan+1−x.
Hence 1a0−xa0a1=1a0+y0=1a0+a0xa1−x.
Again, 1a0−xa0a1+x2a0a1a2=1a0−xa0(1a1−xa1a2)=1a0−xa0(a1+y1)
=1a0+a0xa1+y1−x
=1a0+a0xa1−x+a1xa2−x;
and generally 1a0−xa0a1+x2a0a1a2−⋯+(−1)nxna0a1a2…an
=1a0+a0xa1−x+a1xa2−x+⋯an−1xan−x.