1.(1/2）^6*2^9
=1/2^6*2^9
=2^3
=8
2.(1/4)^10*2^20
=(1/2^2)^20-2^20
=1/2^20*2^20
=1
3.(-6*6^-2)^-2-(-2^2)2
=(-6*1/6^2)^-2-(-4)2
=(-1/6)^-2+8
=36+8
=44