Question

初一的3条解方程,虽然3条,2/X+3 + 3/X-4=a-b/2(a+b) - a^2+b^2/a^2-b^2=1/x

Answer 1

2/X+3 + 3/X-4=0

2(x-4)+3(x+3)=0

2x-8+3x+9=0

5x=-1

x=-1/5

a-b/2(a+b) - a^2+b^2/a^2-b^2

=(a-b)²/2(a+b) -2(a²+b²)/2(a²-b²)

=(-a²-2ab-b²)/2(a²-b²)

=-(a+b)²/2(a²-b²)

=-(a+b)/2(a-b)

1/x-1 - x^2+2x/x^3-1

=1/(x-1)-(x²+2x)/(x-1)(x²+x+1）

=(x²+x+1-x²-2x)/(x-1)(x²+x+1）

=(1-x)/(x-1)(x²+x+1）

=-1/(x²+x+1）