ta có:
(2x-4)^2>0
|y-5|>0
(x+y-z)^6>0
=>(2x-4)^2+|y-5|+(x+y-z)^6>0
mà theo đề:(2x-4)^2+|y-5|+(x+y-z)^6=0
=>(2x-4)^2=|y-5|=(x+y-z)^6=0
+)(2x-4)^2=0=>2x-4=0=>2x=4=>x=2
+)|y-5|=0=>y-5=0=>y=5
+)(x+y-z)^6=0=>x+y-z=0
thay x=2;y=5 vào x+y-z=0
=>2+5-z=0
=>7-z=0
=>z=7
vậy..
nhớ tick