已知m>4,化简:|m-4|+|7-2m|+|m^2-2m+1|-|m^2-2m-3|

• .1.参考答案-1
  ∵m>4
  ∴m-4>0,7-2m0,m+1>0,m-3>0
  ∴(m+1)(m-3)>0
  ∴原式=|m-4|+|7-2m|+|(m-1)²|-|(m+1)(m-3)|
  =m-4+2m-7+(m-1)²-(m+1)(m-3)
  =3m-11+m²-2m+1-m²+2m+3
  =3m-7
• .2.参考答案-2
  原式=3M-7
• .3.参考答案-3
  |m-4|+|7-2m|+|m^2-2m+1|-|m^2-2m-3|
  = m-4+2m-7+m^2-2m+1-m^2+2m+3
  =3m-7
• .4.参考答案-4