如图,在□ABCD中,DE平分∠ADC,AD=6,BE=2,则□ABCD的周长是________.
已知:(x3n-2)2x2n+4÷xn=x2n-5,则n=______.
若5x-3y-2=0,则105x÷103y= .
若,则a的值是_______.
(-x)10÷(-x)5÷(-x)÷x=_____.
计算:________;(xy)6÷(xy)3=______.