8分之7-0.8x=0.625

通分(2x+13)/(x²+13x+40)/(2x+13)/(x²+13x+42)因为x²+13x+40≠x²+13x+42所以2x+13=0x=-13/2

X+1分之X+2+X+7分之X+8=X+5分之X+6+X+3分之X+4等式两边各2个x常数和都为10所以都约去得1／x＋7／x＝5／x＋3／x为恒等式所以x为不等于零的任意实数再问：������ڶ�Щ

x=175/16

5分之1(x-8)+4分之1x+7分之x-1=6-5分之23-x28(x-8)+35x+20(x-1)=840-28(23-x)28x-224+35x+20x-20=840-644+28x55x=44

请加括号再问：没有括号再答：是这样吗？x/(x-2)+x/(x-7)-9=x/(x-1)+1+x/(x-6)-8再问：是：x/(x-2)+(x-9)/(x-7)=(x+1)/(x-1)+(x-8)/(

x+1分之x+2减去x+3分之x+4=x+5分之x+6减去X+7分之x+8方程两边分别通分,得[(x+2)(x+3)-(x+1)(x+4)]/[(x+1)(x+3)]=[(x+6)(x+7)-(x+8

x+2分之x+1+x+9分之x+8=x+3分之x+2+x+8分之x+7即x+2分之1+x+9分之1=x+3分之1+x+8分之1即x+2分之1-x+3分之1=+x+8分之1-x+9分之1（x＋2）（x＋

希望能帮上忙,第一步x-7/x-9+x-3/x-5=x-4/x-6+x-6/x-8第二步(x-9)+2/x-9+(x-5)+2/x-5=(x-6)+2/x-6+(x-8)+2/x-8第三步1+2/x-

X-3X/8=5/75X/8=5/7X=8/7

由(x-4)/(x-5)-(x-5)/(x-6)=(x-7)/(x-8)-(x-8)/(x-9)得：（X-4）/（X-5）-（X-7）/（X-8）=（X-5）/（X-6）-(X-8）/（X-9）即：【

0.8x-7.5=0.50.8X=0.5+7.50.8X=8X=8除以0.8X=101-10分之7x=4分之17\10X=1-1\47\10X=3\4X=3\4*10\7X=15\143分之1x÷5分

因为(x-4)/(x-5)=[(x-5)+1]/(x-5)=1+1/(x-5)……所以原方程可化为1+1/(x-5)-1-1/(x-6)=1+1/(x-8)-1-1/(x-9)1/(x-5)-1/(x

等号前后同时分别计算减法得：(x+1)(x+3)分之2=(x+5)(x+7)分之2所以：(x+1)(x+3)=(x+5)(x+7)x^2+4x+3=x^2+12x+35x=-4

因为(x-4)/(x-5)=[(x-5)+1]/(x-5)=1+1/(x-5)……所以原方程可化为1+1/(x-5)-1-1/(x-6)=1+1/(x-8)-1-1/(x-9)1/(x-5)-1/(x

(x-4）/(x-5)-(x-5)/(x-6)=(x-7)/(x-8)-(x-8)/(x-9)对方程两边各自通分：[(x-4)(x-6)-(x-5)(x-5)]/[(x-5)/(x-6)]=[(x-7

每个分式减去1(x-4-x+5)/(x-5)+(x-8-x+9)/(x-9)=(x-7-x+8)/(x-8)+(x-5-x+6)/(x-6)1/(x-5)+1/(x-9)=1/(x-8)+1/(x-6

x+0.25x=7分之81.25x=7分之8x=35分之32再问：����1.25x=7��֮8������ϸ����лл再答：1.25x=7��֮84��֮5x=7��֮8x=7��֮8��4��֮

解方程两边同时乘以35得：28x+15x=28043x=280x=280/43再问：详细一点可以吗

(x+7)/(x+6)+(x+9)/(x+8)=(x+10)/(x+9)+(x+6)/(x+5)1+1/(x+6)+1+1/(x+8)=1+1/(1+9)+1+1/(x+5)1/(x+6)+1/(x+

通分(x+5+x+8)/(x+5)(x+8)=(x+6+x+7)/(x+6)(x+7)(2x+13)/(x^2+13x+40)=(2x+13)/(x^2+13x+42)(2x+13)[1/(x^2+1