方程3.5(X+7)=25.

方程3.5(X+7)=25.


3.5x+24.5=25.9
3.5x=25.9-24.5
3.5x=1.4
x=0.4



解因式方程:x-4/x-5+x-8/x-9=x-7/x-8+x-5/x-6


(x-4)/(x-5)+(x-8)/(x-9)=(x-7)/(x-8)+(x-5)/(x-6)
1+1/(x-5)+1+1/(x-9)=1+1/(x-8)+1+1/(x-6)
1/(x-5)+1/(x-9)=1/(x-8)+1/(x-6)
(2x-14)/[(x-5)(x-9)]=(2x-14)/[(x-8)(x-6)]
當x≠7時,
(x-5)(x-9)=(x-8)(x-6)
-14x+45=-14x+48
45=48
∵45≠48
∴x=7