Question

（X-5+16/X+3）÷X-1/X2²-9 （b/a+b-2ab/a²-b²）÷a+1/b-a

（X-5+16/X+3）÷X-1/X2²-9
（b/a+b-2ab/a²-b²）÷a+1/b-a（X²/X-1+1/1-X）1/X 其中X=-1/2
跪求！！！

Answer 1

猜[X-5+16/(X+3）]÷[(X-1)/(X²-9)]
=(x^2-2x-15+16)/(x+3)*(x+3)(x-3)/(x-1)
=(x-1)^2*(x-3)/(x-1)
=(x-1)(x-3)
=x^2-4x+3.

[b/(a+b)-2ab/(a²-b²）]÷(a+1)/(b-a)
=[b(a-b)-2ab]/[(a+b)(a-b)]*（b-a）/(a+1)
=b(-a-b)/[(a+b)(a-b)]*(b-a)/(a+1)
=b/(a+1).

[X²/(X-1)+1/(1-X）]+1/X
=(x^2-1)/(x-1)+1/x
=x+1+1/x,
当x=-1/2时原式=1/2-2=-3/2.

Answer 2

1