先化简再求值x(x²-3)+x²(x-3)-3x(x²-x-1)
来源:学生作业帮助网 编辑:作业帮 时间:2024/08/19 04:38:12
![先化简再求值x(x²-3)+x²(x-3)-3x(x²-x-1)](/uploads/image/f/2039970-66-0.jpg?t=%E5%85%88%E5%8C%96%E7%AE%80%E5%86%8D%E6%B1%82%E5%80%BCx%28x%C2%B2-3%29%2Bx%C2%B2%28x-3%29-3x%28x%C2%B2-x-1%29)
1+(2x-4)/(x^2-a-2)]/[(x+3)/(x^2-1)]={1+2(x-2)/[(x-2)(x+1)]}(x^2-1)/(x+3)=[1+2/(x+1)](x+1)(x-1)/(x+3)
题目有误吧(x-x)x-1分之4(x-x)+(x-2)再问:(x方-x)(x-2)方再答:
[(x+2)/(x^2-2x)-(x-1)/(x^2-4x+4)]÷[(4-x)/x]=[(x+2)/x(x-2)-(x-1)/(x-2)²]÷[(4-x)/x]=[(x+2)(x-2)-x
(3x/x-1-x/x+1)*x^2-1/2x,其中x=-3=(3x^2+3x-x^2+1)/(x-1)(x+1)*(x+1)(x-1)/2x=(2x^2+x+1)/2x=x+1/2+1/2x=-3+
=x+(3x-2x)+(5x-4x)+……+(101x-100x)=x+x+……+x=51x=51×2/51=2
x²(3-x)+x(x²-2x)+1=3x²-x³+x³-2x²+1=x²+1=3+1=4
[x-x/(x+1)][(x+1)/(x^2+4x+4)][(x^2-4)/(x^2-2x)]=[x^2/(x+1)][(x+1)/(x+2)^2][(x+2)(x-2)/x(x-2)]=x/(x+2
3x^3-[-x^2-2(x-x^6)]=3x^3+x^2+2(x-x^6)=3x^3+x^2+2x-2x^6x=-1原式=-3+1-2-2=-6
=(x/x^2-1)*[(x^2+2x+1)/(x^2+4x+3)]=[x/(x+1)(x-1)]*[(x+1)^2/(x+3)(x+1)]约去相同项得=x/[(x-1)(x+3)]
(x+2/x²-2x-x-1/x²-4x+4)÷x-4/x={(x+2)(x-2)/[x(x-2)²]-x(x-1)/[x(x-2)²]}·x/(x-4)={(
再问:(x加2)吗?再答:什么?再问:第一个括号里的是x加几
小括号内先通分:分母为x平方-4,分子为3x平方+6x,另一个是x平方-2x化简:{x²-4分之2x²+8x}÷x²-4分之2x结果=x+4
[x^2-9]/[x^2+6x+9]】×【[3x^3+9x^2]/[x^2-3x]】=(x+3)(x-3)/(x+3)²*(3x²(x+3)/x(x-3))=(x-3)/(x+3)
∵|x|=3∴x=3或x=-33x²+(2x²-3x)-(-2x+x²)=3x²+2x²-3x+2x-x²=4x²-x当x=3时,
3x^2-[7x^2-2(x^2-3x)-2x]=3x^2-[7x^2-2x^2+6x-2x]=3x^2-[5x^2+4x]=3x^2-5x^2-4x=-2x^2-4x=-2x(-2)^2-4x(-2
x^3-2x^2+4x/x^2-4x+4÷x^2-2x+4/x-2=x(x²-2x+4)/(x-2)²÷(x-2)/(x²-2x+4)=x(x²-2x+4)/(
[3x/(x+2)-x/(x-2)]÷2x/(x^2-4)分子分母同时乘以x²-4=[3x(x-2)-x(x+2)]/2x=(3x²-6x-x²-2x)/2x=(2x
原式=9x+6x2-3x+2x2=8x2+6x当x=-2时原式=8×(-2)2+6×(-2)=32-12=20.
6x(x²-x+1)-(2x+3)(3x-2)=6x³-6x²+6x-(6x²-4x+9x-6)=6x³-6x²+6x-6x²-5
(x-4)(x-2)-(x-1)(x-3)=x²-6x+8-x²+4x-3=-2x+5当x=-5/2时原式=-2*(-5/2)+5=5+5=10