2x 5分之x-3≤x 1分之2x-3

(2x-y)/(x+3y)=2所以原式=2(2x-y)/(x+3y)-3(x+4y)/(2x-y)=2(2x-y)/(x+3y)-3/[(2x-y)/(x+3y)]=2×2-3/2=5/2

6x-10=3x+8→3x=18→x=615x+9=5x+199→10x=190→x=194x+2=3x+6→x=46分之1x+2分之7=2分之21→6分之1x=7→x=42答完给分PS：我也匿名是对

原式=(x-1)(x-2)/(x-2)(x-3)*(x-3)(x-4)/(x-1)(x-4)=1有疑问,请追问；若满意,请采纳,谢谢!

=[(1+1/3)*.(1+N/(N+2)],（N》1）,=（4/3）*（6/4）*.（N+2+N）/（N+2)=（4/3）*（6/4）*...（2N+2）/（N+2）={【2*3*...（N+1）】

2/5：x＝2/3:8x×（2/3）=8×（2/5）=16/5x=（16/5）÷（2/3）=24/51.7x-0.4x＝3.91.3x=3.9x=3.9÷1.3=3

2X1+X2+X3+X4+X5=6①X1+2X2+X3+X4+X5=12②X1+X2+2X3+X4+X5=24③X1+X2+X3+2X4+X5=48④X1+X2+X3+X4+2X5=96⑤①+②+③+

X拔*5=(X1+X2+X3+X4+X5)=>X1+1+X2+2+X3+3+X4+4+X5+5=X拔*5+15故新平均数是（X拔*5+15）/5=X拔+3

2x/3=x²/12+3/x²+4/xx²/12+3/x²=2x/3-4/xx²/4+9/x²=2x-12/x(x/2-3/x)²

利用x1+X2=-B/A,x1x2=C/A(1)1/x1+1/x2=(x1+x2)/x1x2=-(-6/2)/(3/2)=-2(2)在菱形ABCD中边长是5,所以有OA^2+OB^2=5^2=25OA

[(x-2)分之3x-(x+2)分之x]乘x分之(x²-4)=[(x-2)分之3x]乘x分之(x²-4)-[(x+2)分之x]乘x分之(x²-4)=3(x+2)-(x-2

X+（X+12)x5分之4=42X+0.8X+9.6=421.8X=32.4X=18X+（X+28）x4分之3=42X+0.75X+21=421.75X=63X=36X+(15+X)x5分之2=69X

(x-3)分之x-(x^2-3x)分之(x+6)+x分之1等于几?=x²/x(x-3)-(x+6)/x(x-3)+(x-3)/x(x-3)=(x²-x-6+x-3)/x(x-3)=

x/4+0.75x=1/82x+0.75=12x=0.25x=0.1254（x+0.2）=1.24x=1.2-0.84x=0.4x=0.15x-1/3=2/315x-1=215x=3x=0.2可以重新

(2x-5)/6≤(3x+1)/4-2x/32(2x-5)≤3(3x+1)-8x4x-10≤9x+3-8x3x≤13x≤13/3

（1）解是x1等于a,x2等于a分之2（2）在方程x+X分之2=a+a分之2两边同时乘以ax,得出a乘以(x的平方)+2a=（a的平方）乘以x+2x,移项后得到a乘以(x的平方)-（a的平方+2）乘以

x1+x2=-3/2x1x2=-21/x1+1/x2=（x1+x2)/x1x2=(-3/2)/(-2)=3/4x1²+x2²=(x1+x2)²-2x1x2=(-3/2)&

X1+X2=-6/2=-3X1*X2=-3/21/X1+1/X2=(X1+X2)/(X1X2)=-3/(-3/2)=2

3分之3x-2-3分之9-2x≤2分之5x+1x-2-3-2x≤2.5x+1-x-5≤2.5x+13.5x+6≥0x≥-12/7