Question

[THAO MIU]

tim so nguyen x biet rang 

(x-5)^4=(x-5)^6

Answer 1

[Nguyễn Vũ Dũng]

(x-5)^6-(x-5)^4=0

(x-5)^4.[(x-5)^2-1]=0

=>2 trường hợp 

(x-5)^4=0=>x-5=0=>x=5

(x-5)^2-1=0 =>(x-5)^2=1=>x-5=-1;1

=>x={4,9}

Vậy x={4,5,9}