Question

(x-7)^x+1 -(x-7)^x+11=0

Answer 1

(x-7)^x+1-(x-7)^x+11=0

=>(x-7)^x+1-(x-7)^x+1.(x-7)^x+10=0

=>(x-7)^x+1.[1-(x-7)^x+10]=0

TH1:(x-7)^x+1=0=>x=7

TH2:1-(x-7)^x+10=0=>(x-7)^x+10=1=>x=8 hoặc x=6

Vậy x E {6;7;8}