若m+n=3 b²-a²=2030则2m²+4mn+2n²+(a+b)(a-b)的值为
问题描述:
若m+n=3 b²-a²=2030则2m²+4mn+2n²+(a+b)(a-b)的值为
答
2m²+4mn+2n²+(a+b)(a-b)
=2(m²+2mn+n²)+a²-b²
=2(m+n)²-(b²-a²)
=2×3×3-2030
=-2012