通分1/a²-3a , 1/a²-9和 3/x²-2x, 2x+1/x²-4, 3/2x²+4x

通分1/a²-3a , 1/a²-9和 3/x²-2x, 2x+1/x²-4, 3/2x²+4x
通分1/a²-3a , 1/a²-9和 3/x²-2x, 2x+1/x²-4, 3/2x²+4x

通分1/a²-3a , 1/a²-9和 3/x²-2x, 2x+1/x²-4, 3/2x²+4x
1/a²-3a=1/a(a-3)=(a+3)/a(a+3)(a-3)
1/a²-9=1/(a+3)(a-3)=a/a(a+3)(a-3)
3/x²-2x=3/x(x-2)=6x+12/2x(x+2)(x-2)
2x+1/x²-4=2x+1/(x+2)(x-2)=4x²+2x/2x(x+2)(x-2)
3/2x²+4x=3/2x(x+2)=3x-6/2x(x+2)(x-2)

通分1/a²-3a =1/a(a-3)=(a+3)/a(a-3)(a+3)，
1/a²-9=1/(a-3)(a+3)=a/a(a-3)(a+3)
3/x²-2x=3/x(x-2)=3*2(x+2)/ 2x(x+2)(x-2)
2x+1/x²-4=(2x+1)/(x+2)(x-2)=2x(2x+1)/2x(x+2)(x-2)
3/2x²+4x=3/2x(x+2)=3(x-2)/2x(x+2)(x-2)