七年期数学课课精练的一道题

来源：百度知道 编辑：UC知道 时间：2024/04/28 16:51:30
已知m,x,y满足条件①5/2(x-2)^2+3/4|m|=0,②-2a^2b^y+1与3a^2b^3是同类项,求代数式0.375x^2y+5m^2x-｛-7/16x^2y+[-1/4xy^2+(-3/16x^2y-3.475xy^2)]-6.275xy^2｝
要过程！~急啊！~

5/2(x-2)^2+3/4|m|=0
绝对值和平方大于等于0，相加等于0
所以都等于0
x-2=0,x=2,m=0

-2a^2b^y+1与3a^2b^3是同类项
所以b的系数相等
所以y+1=3,y=2

0.375x^2y+5m^2x-｛-7/16x^2y+[-¼xy^2+(-3/16x^2y-3.475xy^2)]-6.275xy^2｝
先把m=0代入
=0.375x^2y-｛-7/16x^2y+[-¼xy^2+(-3/16x^2y-3.475xy^2)]-6.275xy^2｝
=0.375x^2y-｛-7/16x^2y+[-3/16x^2y-3.725xy^2]-6.275xy^2｝
=0.375x^2y-(-0.625x^2y-3.725xy^2-6.275xy^2)
=0.375x^2y+0.625x^2y+3.725xy^2+6.275xy^2
=x^2y+10xy^2
=8+10*8
=88

兄弟呀我也不会 但我7年纪有此和你一样 做到了12点 悬赏了400分