化简3x² 8x-3
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x-(3x-8)/2
|x-1|+|x-10|表示数轴上x到1的距离+x到10的距离.显然最小值是9,此时x只要在1到10之间就好.类似的,|x-2|+|x-9|的最小值是7,此时x在2到9之间就好.|x-3|+|x-8|
x(1+2+...+9)=x(9-8-7-...-1)x=0记得采纳啊
是9x-x³原式=(x²+3x+9)/(x-3)(x²+3x+9)-6x/x(x-3)(x+3)-(x-1)/2(x+3)=1/(x-3)-6/(x-3)(x+3)-(x
x+x^2+x^3+x^4+x^5+x^6+x^7+x^8=(x+x^2+x^3+x^4)+(x^5+x^6+x^7+x^8)=x(1+x+x^2+x^3)+x^5(1+x+x^2+x^3)=(x+x
原式=(x+2)/x(x+1)+(2x+1)/(x+1)(x+2)-(x-3)/x(x+2)=[(x+2)^2+x(2x+1)-(x+1)(x-3)]/x(x+1)(x+2)=(x^2+4x+4+2x
-(x²-2x)+(-3x+2x²)=-x²+2x-3x+2x²=x²-x=x(x-1)-2(a²-3ab)-3(ab-2a²)=
1+x+x^2+x^3=0x+x^2+x^3+x^4+x^5+x^6+x^7+x^8=(x+x^2+x^3+x^4)+(x^5+x^6+x^7+x^8)=x(1+x+x^2+x^3)+x^5(1+x+
设x1=4-√3,x2=4+√3,是方程X^2-8X+13=0的两根所以X1^2-8X1+15=2X^4-6X^3-2X^2+18X+23=(X+1)^2*(X^2-8X+13)+10=10所以原式=
(x+2x+3x+.100x)=(1+2+3...+100)x=100(100+1)x/2=5050x
3x-1>x+12x>2x>1x+89x>3所以x>3
(x^3-3x^2-x+3)=(x^3-x)-3(x^2-1)=x(x^2-1)-3(x^2-1)=(x-3)((x^2-1)所以原式=(x-3)((x^2-1)、(x-2)分母是x-3就更好了.!
化简:1/x(x+1)+1/(x+1)(x+2)+1/(x+2)(x+3)+...+1/(x+8)(x+9)=1/x-1/(x+1)+1/(x+1)-1/(x+2)+1/(x+2)-1/(x+3)+.
2(X-8)(X+5)-(2X-1)(X+2)=2(X^2-3X-40)-(2X^2+3X-2)=2X^2-6X-80-2X^2-3X+2=-9X-78当X=-7时原式=-9*(-7)-78=-15(
原式=1x-1x+1+1x+1-1x+2+1x+2-1x+3+1x+3-1x+4=1x-1x+4=4x(x+4).
原式=1/x-1/(x+1)+1/(x+1)-1/(x+2)+1/(x+2)-……-1/(x+2007)+1/(x+2007)-1/(x+2008)=1/x-1/(x+2008)=2008/[x(x+
9x-12x+5x=-3x+5x=2x3x-5x-2+5x+8=-2x+5x-2+8=3x+63x+5+2x+3-7-11x=3x+2x-11x+5+3-7=5x-11x+8-7=-6x+1
(x+2)(x-2)+x(3-x)=x²-4+3x-x²=3x-4
x/(3x-5)分母用十字交叉法
原式=[(2X-3)/X-X/X]/[(X+3)(X-3)/X]=[(2X-3-X)/X]/[(X+3)(X-3)/X]=[(X-3)/X]×[X/(X+3)(X-3)]=X(X-3)/[X(X+3)