Question

∣m+4 ∣与n²-2n+1互为相反数，把多项式x²+4y²-mxy-n分解因式

Answer 1

解：由题意可得：∣m+4 ∣+ n²-2n+1=0               
 即 ∣m+4∣+（n-1）²=0                 
所以   
解得
所以x²+4y²-mxy-n= x²+4y²+4xy-1                            
=(x+2y)²-1                                  
=(x+2y+1)(x+2y-1)