初二数学（1）若2x-y=0,求4x³+2xy(x+y)+y的值 2）若m²+m-1=0,求m³+2m²+2008的值

初二数学（1）若2x-y=0,求4x³+2xy(x+y)+y的值 2）若m²+m-1=0,求m³+2m²+2008的值
初二数学（1）若2x-y=0,求4x³+2xy(x+y)+y的值 2）若m²+m-1=0,求m³+2m²+2008的值

初二数学（1）若2x-y=0,求4x³+2xy(x+y)+y的值 2）若m²+m-1=0,求m³+2m²+2008的值
(1).2x-y=0 y=2x (2).m²+m-1=0 m²+m=1 m(m+1)=1
4x³+2xy(x+y)+y m³+2m²+2008
=4x³+2x×2x(x+2x)+2x =m²(m+1)+m²+2008
=4x³+12x³+2x =m+m²+2008
=16x³+2x =1+2008
=2009

（1）若2x-y=0
所以y=2x
故4x³+2xy(x+y)+y
=4x³+2x*2x(x+2x)+2x
=16x³+2x

2）若m²+m-1=0
所以m²=1-m
所以m³+2m²+2008
=m²(m+2)+2008
=(1-m)(m+2)+2008
=-(m²+m)+2+2008
=-1+2+2008=2009

先解第二个：m2＝1＋m
m(1-m)+2(1-m)+2008用m代替m2从而降次
m-m2+2-2m+2008又出现讨厌的m2。。。再降！
m-1+m+2-2m+2008 m被消掉了（开心）
=2009

第一个让我想想等等啊～