大师作文网15*0.9 (X-15)*3=25.5
来源：学生作业帮助网 编辑：作业帮 时间：2024/11/11 12:45:32
1x+2x+3x+4x+5x+6x+7x+8x+9x+10x+11x+12x+13x+14x+15x=550120x=550x=55/12=4.583
(x-3)/5x=2/1515(x-3)=10x15x-45=10x5x=45x=9
4.5x-3/4x=154.5X-0.75X=153.75X=15X=4
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=36
(5X-15)-(2X+3)=X+123x-18=x+122x=30x=15
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/2（1/1-1/3+1/3-1/5+1/5-1/7+1/7-1/9+1/9-1/11)=1x/2*10/11=110x=22x=11/5这回的方法是你想要的了吧
10-3x=410-4=3x6=3x∴x=20.9x=8.1x=915x-7.5x=157.5x=15x=20.8x+0.4x=1.21.2x=1.2x=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=
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)
7X=2X+1515=7X-2X15=5X5X=15X=15/5X=3正确啊
45x-120-8x-12=24x-24-445x-8x-24x=120+12-24-413x=104x=104÷13x=8
1/2x－28=501/2x=50+28=78x=156x－2/7x=15/285x/7=15/28x=3/43x－1.2=3.63x=3.6+1.2=4.8x=1.6x－20％x=7.280%x=7
15+1=3x-x16=2xx=16/2x=8
.3x+1=15-x3x+x=15-14x=14x=14/4x=7/2.
2x等于x+15x等于15
15-4+5X=2X+35-3X11+5X-2X+3X=356X=35-116X=24X=4