已知m+n=¾,m-n=¼,求m2-2mn+3m+3n+n2的值
问题描述:
已知m+n=¾,m-n=¼,求m2-2mn+3m+3n+n2的值
答
m2-2mn+3m+3n+n2
=(m-n)²+3(m+n)
=(1/4)²+3*3/4
=1/16+9/4
=37/16
答
m2-2mn+3m+3n+n2
=(m-n)2+3(m+n)
=1/4×2+3×3/4
=1/2+9/4
=11/4