已知m加n等于4分之3,m减那等于4分之1求m方减2mn加3m加3n加n方
问题描述:
已知m加n等于4分之3,m减那等于4分之1求m方减2mn加3m加3n加n方
答
m2-2mn+3m+3n+n2
=m2-2mn+n2+3m+3n
=(m-n)2+3(m+n)
=(1/4)2+3x(3/4)
=1/16+9/4
=37/16
答
m²-2mn+3m+3n+n²
=(m-n)²+3(m+n)
=1/16+9/4
=37/16