4×15x=18(52-x)

4x²-3x=52x²-(3x/4)=13x²-(3x/4)+(3/8)²=13+(3/8)²(x-3/8)²=841/64x-3/8=±√

x加30%x=521.3x=52x=52×1.3x=40x减40%x=150.6x=15x=15÷0.6x=2550%x加x=31.51.5x=31.5x=31.5÷1.5x=21x减1%x=19.8

3x-18=13.23x=13.2+18x=10.41.5x-x=60.5x=6x=6/0.5=124x+1.2x=265.2x=26x=5

5x^2-18=9xx^2-9x/5=18/5(x-9/10)^2=18/5+81/100(x-9/10)^2=441/100x-9/10=21/10x1=31/10x-9/10=-21/10x2=-

是这样的：x^5+x^4=x^3(x^2+x)=(x^2+x)[(x^3-1)+1]=(x^2+x)(x^3-1)+x^2+x=[x(x+1)(x-1)](x^2+x+1)+x^2+x=(x^3-x)

32＋x=58x=58-32x=26x-4.2=0.79x=0.79+4.2x=4.994x=44x=44÷4x=11x÷18=29x=29×18x=5226x=30x=30÷6x=515÷x=0.5

1x+2x+3x+4x+5x+6x+7x+8x+9x+10x+11x+12x+13x+14x+15x=550120x=550x=55/12=4.583

6x^2-7x+1=0(6x-1)(x-1)=0x1=1/6;x2=15x方-18=9x变为5x^2-9x-18=0(5x+6)(x-3)=0x1=-6/5;x2=34x^2-3x=52变为4x^2-

x^4-4x^3-4x^2+15x+18=0x^4-3x^3-x^3+3x^2-7x^2+21x-6x+18=0(x-3)(x^3-x^2-7x-6)=0x1=3x2=3.49449283705542

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=

1/[x(x+3)]+1/[(x+3)(x+6)]+.+1/[(x+15)(x+18)]=1/3[1/x-1/(x+3)]+[1/(x+3)-1/(x+6)]+.+[1/(x+15)-1/(x+18)

错了吧,是-9x2x²-5x=1原式=15x²-18x+4+3x²-18x+32-9x=18x²-45x+36=9(2x²-5x)+36=9+36=4

4x+18=5x-1518+15=5X-4X33=X

∵(x^4-4x^2+5x-15)/[(x^2+1)(x-2)]=[(x^4+x²-5x²-5)+(5x-10)]/[(x²+1)(x-2)]=[x²(x&su

x^6+x^5(-1-3)+x^4(-4+3+1)+x^3(7+12-1-2)+x^2(-21-4+2)+x(7+8)-14+6x^2-15x+18=0x^6-4x^5+16x^3-17x^2+4=0

你这题显然,打错了已知条件建议改为x=13/√(19+8√3)=13/√(4+√3)^2=13/(4+√3)=4-√34-x=√3两边平方x^2-8x+13=0(X^4-6X^3-2X^2+18X+2

1.6/14X+7/14X=13/14X=13X=142.4/5X=8/15X=2/33.9X=18/11X=2/11这种题目多做做熟悉熟悉就会了哦～

5x^-18=9x5x^-9x-18=0(x-3)(5x+6)=0x=3x=-6/54x^-3x=524x^-3x-52=0(x+13)(4x-4)=0x=-13x=15x^=4-2x5x^+2x-4

x=根号下19-8倍根号3=根号下[4^2+(根号3)^2-2*4*根号3]=根号(4-根号3)^2=4-根号3x-4=-根号3(x-4)^2=3x^2-8x+13=0x^2-8x+13=0,所以x^

2x等于x+15x等于15