求帮忙数学
3个回答
展开全部
19. 0.37x^2y-(1/2)y^2x-(1/3)xy^2+0.13yx^2+(1/2)
=0.5x^2y-(5/6)xy^2+(1/2)
=-(5/6)xy^2+0.5x^2y+(1/2).
20. (4/3)x^3-(3/7)x^2+(2/3)x^3+5x-(4/7)x^2+3
=2x^3-x^2+5x+3
当 x=1/2 时,原式的值=2x(1/2)^3-(1/2)^2+5x(1/2)+3
=1/4-1/4+5/2+3
=11/2
=5.5.
=0.5x^2y-(5/6)xy^2+(1/2)
=-(5/6)xy^2+0.5x^2y+(1/2).
20. (4/3)x^3-(3/7)x^2+(2/3)x^3+5x-(4/7)x^2+3
=2x^3-x^2+5x+3
当 x=1/2 时,原式的值=2x(1/2)^3-(1/2)^2+5x(1/2)+3
=1/4-1/4+5/2+3
=11/2
=5.5.
更多追问追答
追问
请问19题Y的升幂怎么排列,谢谢
错了,是降幂
展开全部
19.
0.37x²y-1/2y²x-1/3xy²+0.13yx²+1/2
=0.5x²y-5/6xy²+1/2
=-5/6xy²+0.5x²y+1/2
20.
4/3x³-3/7x²+2/3x³+5x-4/7x²+3 x=1/2
=2x³-x²+5x+3
=2*(1/2)³-(1/2)²+5*1/2+3
=1/4-1/4+5/2+3
=11/2
0.37x²y-1/2y²x-1/3xy²+0.13yx²+1/2
=0.5x²y-5/6xy²+1/2
=-5/6xy²+0.5x²y+1/2
20.
4/3x³-3/7x²+2/3x³+5x-4/7x²+3 x=1/2
=2x³-x²+5x+3
=2*(1/2)³-(1/2)²+5*1/2+3
=1/4-1/4+5/2+3
=11/2
追问
最后一题好像错了
已赞过
已踩过<
评论
收起
你对这个回答的评价是?
推荐律师服务:
若未解决您的问题,请您详细描述您的问题,通过百度律临进行免费专业咨询