Question

\(\dfrac{8-x}{x-7}-8=\dfrac{1}{x-7}\)

Answer 1

\(\Leftrightarrow\dfrac{8-x-8\left(x-7\right)-1}{x-7}=0\)

\(\Leftrightarrow8-x-8x+56-1=0\)

\(\Leftrightarrow-9x+63=0\)

\(\Leftrightarrow-9x=-63\)

\(\Leftrightarrow x=7\)

Answer 2

\(\leftrightarrow\)\(\dfrac{8-x}{x-7}-\dfrac{8\left(x-7\right)}{x-7}=\dfrac{1}{x-7}\)

ĐKXĐ: x\(\ne\)7

\(\rightarrow\)\(8-x-8x+56=1\)

\(\leftrightarrow-9x=1-8-56\)

\(\leftrightarrow-9x=-63\)

\(\leftrightarrow x=7\)(KTMĐK)

Vậy phương trình có tập nghiệm S=\(\varnothing\)