x=1:0.00001:12; matlab-搜答案-智慧作业帮

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

2x(x-1)-x(3x+2)=-x(x+2)-122x^2-2x-3x^2-2x=-x^2-2x-122x^2-3x^2+x^2-2x-2x+2x=-12-2x+12=0-2(x-6)=0x-6=0

(x+2-12/x-2)/(4-x)/(x-2),其中x=-1/2=(x²-4-12)(x-2)÷(4-x)/(x-2)=(x²-16)/(4-x)=-(4-x)(4+x)/(4-

4/x+4=3/x+1/x+12

两边同时乘以x(x+4)(x+12)4x(x+12)=3(x+4)(x+12)+x(x+4)4x²+48x=3(x²+16x+48)+x²+4x144+4x=0得x=-3

对不等式变形有[x-x^2+7x-12]/(x^2-7x+12)>=0,又因为x^2-7x+12=(x-3)(x-4)-x^2+8x-12=-(x-2)(x-6),于是有-(x-2)(x-3)(x-4

(1)12x+36-6x=102则：6x=66所以：x=11(2)2x-48-x=54,即：x=54+48=102(3)2x-1+x=14,即：3x=15,所以：x=5

(x+1)(x+2)(x^2-2x-1)(x-3)(x-4)+24=0(x+1)(x-3)(x+2)(x-4)(x^2-2x-1)+24=0(x^2-2x-3)(x^2-2x-8)(x^2-2x-1)

每个绝对值里都是正数所以原式=x+1+x+3+x+5+……+x+13-x-2-x-4-x-6-……-x-12=x-1*6+13=x+7=π/2+7

=9x^4+4(x+1)-3x^2-7x+1=9x^4-3x^2-3x+5=9x^4-3x(x+1)+5=9x^4-3x×3x^3+5=5

x/2+x/8+x/12+x/20=1

60X+15X+10X+6X=12091X=120X=120/91

x/2+x/6+x/12+x/20+x/30+x/42=136x/42=1x=7/6

x(x+1)=12x^2+x-12=0(x+4)(x-3)=0x1=-4,x2=3

应该是-2x²,不是-3x²3x²-x=1原式=9x^4-3x³+15x³-5x²+3x²-7x+2001=3x²(3x

解(x+1)(x-3)=12

1/6x+1/12x+1/7x+5+1/2x+4=x2/12x+1/12x+6/12x-12/12x+1/7x=-9-1/4x+1/7x=-9-7x+4x=-9*28-3x=-9*28x=84

变形为1/x-1/(x+1)+1/(x+1)-……+1/(x+9)-1/(x+10)=11/121/x-1/(x+10)=11/12x1=-5-1/11*4345^(1/2)x2=-5+1/11*43

x-(1/5+1/5)x-39=39x-2/5x=39+393/5x=78x=78÷3/5x=130x-1/4x-2/5x=112(1-1/4-2/5)x=1127/20x=112x=112÷7/20

（1-1/2）X+(1/2-1/3)X+(1/3-1/4)X+(1/4-1/5)X+(1/5-1/6)X+(1/6-1/7)X=1(1-1/2+1/2-1/3+1/3-1/4+1/4-1/5+1/5-

X-1=3X+32X=-4;X=-2x-3=12-4x5X=15；x=36x-14=5x-10x+1=2-4x5x=1;x=0.2

3x²=10x+83x²-10x-8=0x=(10±√(100+4×3×8)/2*3x=(10±√196)/6x=(10±14)/6∴x1=4x2=-2/33x²-10x