(m-n)^2-3mn(n-m)-10m^2n^2
=(m-n)²+3mn(m-n)-10m²n²
=(m-n+5mn)(m-n-2mn)问一下这题怎么做：已知2x^2-2xy+3与y^2+4x+1互为相反数,求多项式-x^2y^2-25+4xy2x^2-2xy+3与y^2+4x+1互为相反数∴2x²-2xy+3+y²+4x+1=0∴x²-2xy+y²+x²+4x+4=0即(x-y)²+(x+2)²=0∴x-y=0x+2=0∴x=2y=2-x^2y^2-25+4xy=-16-25+16=-25