计算:
(1)-x5·x2·x10;
(2)(-2)9×(-2)8×(-2)3;
(3)a6·a2+a5·a3-2a·a7;
(4)(-a)2·(-a)3·a6.
若am-2=3,am+2=5,则a2m=________.
已知2m×2m×4=28,则m=________.
10m+1×10n-1=__________,-64×(-6)5=__________.
计算:(-b)4·(-b)3·(-b)5=________.
计算:a3·a5=________,x5·x=________.