20x^2-43xy+m=(4x-7y)(5x+n),则m= .n= .

问题描述:

20x^2-43xy+m=(4x-7y)(5x+n),则m= .n= .

20x^2-43xy+m=(4x-7y)(5x+n)=20x²+4xn-35xy-7ny
m=-7ny
-43xy=-35xy+4xn
-8xy=4xn
n=-2y