一道数学等式化简 左边那条式子是怎么化简到右边的??

左边=(-k^2-1/2+1/2)/(2k^2+1) 分子加上1/2，减去1/2
=[-(k^2+1/2)+1/2]/(2k^2+1) 将分子展开。
=-（k^2+1/2)/(2k^2+1)+(1/2)/(2k^2+1)
=-1/2+1/(4k^2+2)
=右边

是右边化简到左边吧？
右边通分再计算就行了。

-k²/(2k²+1)=-1/2*2k²/(2k²+1)=-1/2*(2k²+1-1)/(2k²+1)=-1/2-1/2*(-1)/(2k²+1)=-1/2+1/(4k²+2)

-k^2/(2k^2+1)
=-(k^2+1/2-1/2)/ (2k^2+1)
=-{ (k^2+1/2) - 1/2) } / (2k^2+1)
= - (k^2+1/2) / (2k^2+1) + (1/2) / (2k^2+1)
= - (k^2+1/2) /{2 (k^2+1/2)} + (1/2) / (2k^2+1)
= -1 /2+ 1 / {2 (2k^2+1) }
= -1 /2+ 1 / (4k^2+2)