(1)若M=y的平方=3x,且mn=9x的平方减一的四次方,则N= (2)计算:1.345乘0.345乘2.69减1.345的三次方减

2025-12-17 07:16:38
推荐回答(1个)
回答1:

1,m=y^2-3x,mn=9x^2-y^4=(3x-y^2)(3x+y^2) n=-3x-y^2
2,1.345*0.345*2.69-1.345^3-1.345*0.345^2
=1.345*(0.345*2.69-1.345^2-0.345^2)
=-1.345*(1.345^2-0.345*1.345*2+0.345^2)
=-1.345*(1.345-0.345)^2=-1.345