(5^(1-5n))^2=5^2/5^10n (4^(2n+1))^3=4^6n*4^3 (2.5)^11n=5^11n/2^11n 160=2^5*5 (5^2/5^10n*2^12n*2^6*5^11n/2^11n)/2^5*5=5^2*2^n*5^n*2^6/2^5*5=2^(n+1)5^(n+1)= = 10^(n+1)