因式分解mn(x²+y²)+xy(m²+y²)

问题描述:

因式分解mn(x²+y²)+xy(m²+y²)

mn(x²+y²)+xy(m²+y²)
=mnx²+mny²+xym²+xyn²
=mx(nx+my)+ny(nx+my)
=(mx+ny)(nx+my)