已知16m=4×22n-2,27n=9×3m+3,求(n-m)2019的值.
已知2x=2,4y=6,8z=12,求x,y,z之间的关系.
(1)已知10m=3,10n=2,求103m+2n+3的值;
(2)已知2x+5y-3=0,求4x·32y的值.
计算:
(1)-2(a3)4+a4·(a2)4;
(2)7x4·x5·(-x)7+5(x4)4-(x8)2;
(3)(-x)5·x3-(-x2)4+[-(-x)2·x2]2;
(4)(a2)m·(an)3-(am-1)2·a3n+2.
若3×9m×27m=321,则m=____;若1284×83=2n,则n=____.
[(a2)3]4=____;(-x5)4+(-x4)5=____;(-a3)5·(-a2)3=____;2m·4n=______.