\(\left(-2\right)^{3n+2}:8^n=\left(-2\right)^{3n}.4;8^n\)
Vì n chẵn=>3n chẵn
=>\(\left(-2\right)^{3n}=2^{3n}\)
=>\(2^{3n}.4:8^n=8^n.4:8^n=4\)
n là snt chẵn suy ra n có dạng 2k
ta có;\(\left(-2\right)^{3.2k+2}:8^{2k}=64^k.4:64^k=\left(64^k:64^k\right).4=1.4=4\)