已知m+n=3,mn=15,求m²-mn+n²
问题描述:
已知m+n=3,mn=15,求m²-mn+n²
答
m²-mn+n²
=(m+n)²-3mn
=9-45
=-36
已知m+n=3,mn=15,求m²-mn+n²
m²-mn+n²
=(m+n)²-3mn
=9-45
=-36