2x-10.3x=15的解-搜答案-搜狗做题网

(2x-3)(x-三分之一)=3x的平方-(x+1)(x-1)2x²-3x-2/3x+1=3x²-x²+111/3x=0x=0

方程x(x-3)=6-2x的解

x(x-3)=6-2xx²-3x=6-2xx²-x-6=0(x-3)(x+2)=0x1=3x2=-2

x(x^2-2)+2x^2(x+3)-3x(5x-7)=x(3x^2-9x+17)+2=>x^3-2x+2x^3+6x^2-15x^2+21x=3x^3-9x^2+17x+2=>2x=2x=1

(X-3)平方-(X+3)*(X-3)=(X+1)*(X+2)-(X-1)*(X+4)x^2-6x+9-x^2+9=x^2+3x+2-x^2-3x+4-6x+18=66x=18-66x=12x=2

提出x得到：x*(1-1/2+1/2-1/3+1/3-1/4……+1/2008-1/2009)=2008接着：x*(1-1/2009)=2008最后：x=2009

2x^2-5x-x^2-2x=x^2-6-7x=-6x=6/7

X(X^2-6X-9)-X(X^2-8X-15)+2X(3-X)=X^3-6X^2-9X-X^3+8X^2+15X+6X-2X^2=12x带入X=1/3原式=12*1/3=4

x(x+3)-x(1-2x)=1+3x²x²+3x-x+2x²=1+3x²x²+3x-x+2x²-3x²=12x=1x=2分之1

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(x+1)(x²-2x-4)=0x1=0x2=-1x²-2x-4=0x²-2x+1=5(x-1)²=5x3=1+√5x4=1-√5x³-2x+1=0

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当x＜0或者x＞2时,f（x）＝x³-2x²,f'(x)＝3x²-4x.当0＜x＜2时,f（x）＝2x²-x³,f'(x)＝4x-3x².当

（x+1)/(x+2)+(x+6)/(x+7)=(x+2)/(x+3)+(x+5)/(x+6)(x+2-1)/(x+2)+(x+7-1)/(x+7)=(x+3-1)/(x+3)+(x+6-1)/(x+

5x-24+x-(240-8x-2x+30)=106x-24-(270-10x)=1016x-294=1016x=304x=19再问：为什么是+30而不是-30啊？乘号在前面不变号吧？再答：-2×(x

0.5x+12-0.8x=10.5;0.3x=1.5;x=5;

54啦再问：过程是什么?再答：不对不对再答：是5再答：

x+62/x+63+x+68/x+69=x+63/x+64+x+67/x+68可以把x+62看做x解得x=-4所以x+62=-4x=-66