[tex]2^{30}=(2^3)^{10}=8^{10}\\
3^{20}=(3^2})^{10}=9^{10}=>\\
2^{30}<3^{20}\\
|2^{20}-3^{20}|+|2^{20}+3^{20}|-2\cdot3^{20}=\\
=-(2^{20}-3^{20})+(2^{20}+3^{20})-2\cdot3^{20}=\\
=3^{20}-2^{20}+2^{20}+3^{20}-2\cdot3^{20}=\\
=3^{20}+3^{20}-2\cdot3^{20}=\\
=2\cdot 3^{20}-2\cdot3^{20}=\\
=0[/tex]
