N=6^200+5^1999-4^1988
Uc(N)=Uc(6^200+5^1999-4^1988 )=Uc(6+5-4^2)=
=Uc(11-6)=5 deci este divizibil cu 5
m) 2^2•5^3+(2^9•75•3^4):(2^3•5^2•3^5)]:2^2=
=2^2•5^3+(2^9•5^2•3•3^4):(2^3•5^2•3^5)]:2^2=
=2^2•5^3+(2^9•5^2•3^5):(2^3•5^2•3^5)]:2^2=
=2^2•5^3+2^6:2^2=
=2^2•5^3+2^4=
=2^2•(5^3+2^2)=
=4•(125+4)=
=4•129=516