作业帮 > 数学 > 作业

1、1/2a^2b-5ac-(3a^2c-a^2b)+(3ac-4a^2c) 当a=-1 ,b=2,c=-2 (化简求值

来源:学生作业帮 编辑:神马作文网作业帮 分类:数学作业 时间:2024/11/18 00:08:47
1、1/2a^2b-5ac-(3a^2c-a^2b)+(3ac-4a^2c) 当a=-1 ,b=2,c=-2 (化简求值) 二、计算题 2、(6m^2+4m-3)-(2m^2-4m-1) 3、 (8xy-x^2+y^2)-3(-x^2+y^2+5xy) 4、 (1/4x-2/3x^2y)·(-12xy) 5.(m+3n)^2(m-3n)^2 6 .(2a-b+3c)^2
1、1/2a^2b-5ac-(3a^2c-a^2b)+(3ac-4a^2c) 当a=-1 ,b=2,c=-2 (化简求值
是有点多!1:1/2ab-5ac-(3ac-ab)+(3ac-4ac) =-1/2ab-2ac-7ac 代入a=-1 ,b=2,c=-2 =-1/2×(-1)×2-2×(-1)×(-2)-7×(-1)×(-2) =-1-4+14 =11 2:6m+4m-3-(2m-4m-1) =6m+4m-3-2m+4m+1 =4m+8m-2 3:(8xy-x+y)-3(-x+y+5xy) =8xy-x+y+3x-3y-15xy =2x-2y-7xy 4:(1/4x-2/3xy)×(-12xy) =(1/4x)×(-12xy)-(2/3xy)×(-12xy) =-3xy+8xy 5:(m+3n)(m-3n) =[(m+3n)(m-3n)] =(m-9n) 6:(2a-b+3c) =4a+b+9c-4ab+12ac-6bc