【正确答案】N₁=+0000101，N₂=+0011010
   原码：[N₁]_原=00000101，[N₂]_原=00011010
   因为[N₂]_原＞[N₁]_原，所以
    00011010
   -00000101
   00010101  符号位取反
   [N₁]_原-[N₂]_原=10010101，N₁-N₂=-0010101
   反码：[N₁]_反=00000101，[-N₂]_反=11100101
   [N₁-N₂]_反=[N₁]_反+[-N₂]_反=00000101+11100101=11101010
   N₁-N₂=-0010101
   补码：[N₁-N₂]_补=[N₁]_补+[-N₂]_补=00000101+11100110=11101011
   N₁-N₂=-0010101

【正确答案】N₁=+0.010110，N₂=+0.100110
   原码：[N₂]_原-[N₁]_原=0.100110-0.010110=0.010000
   符号位=1，N₁-N₂=-0.010000
   反码：[N₁-N₂]_反=[N₁]_反+[-N₂]_反=0.010110+1.011001=1.101111
   N₁-N₂=-0.010000
   补码：[N₁-₂]_补=[N₁]_补+[-N₂]_补=0.010110+1.011010=1.110000
   N₁-N₂=-0.010000