已知m²+mn+2n²=11,mn+n²=5,求m²+n²的值.

已知m²+mn+2n²=11,mn+n²=5,求m²+n²的值.
已知m²+mn+2n²=11,mn+n²=5,求m²+n²的值.

已知m²+mn+2n²=11,mn+n²=5,求m²+n²的值.
m²+n²
=m²+mn+2n²-mn-n²
=(m²+mn+2n²)-(mn+n²)
=11-5
=6

两式相减，得m²+n²=6