因式分解: .
若a4•ay=a8,则y=______.
(m﹣n)3(n﹣m)2(m﹣n)=______,0.22003×52002=______.
xm=6,xn=2,则xm+n=______.
若xm=3,xn=2,则xm+n=______.
计算:﹣2x4•x3=______.