按照第一列展开
原式=a×
ab000.0
0a000.0
.
00000.a
+b×(-1)的n+1次方×
b000.0
ab00.0
0ab0.0
.
0000000000ab
=a的n次方+（-1）的n次方×b的n次方我写漏啊上面是n+1次方啊即按照第一列展开原式=a×ab000.....00a000.....0...........00000.....a+b×(-1)的n+1次方×b000.......0ab00.......00ab0.......0.............00000....ab=a的n次方+（-1）的n+1次方×b的n次方