Question

E(x)=$( \frac{x-6}{ x^{2} -25}- \frac{x}{5-x}- \frac{2}{x+5}) : \frac{2 x^{2} +x-6}{ x^{2} -25}$
 stie cineva?
F(x)$( \frac{ 2x^{2}-2x-17 }{ x^{2} -10x+21}- \frac{x+1}{x-7}) : \frac{1}{ x^{2} -9}$

Answer 1

[(x-6)/(x²-25)-x/(5-x)-2/(x+5)] :(2x²+x-6)/(x²-25)=

=(x-6+x²+5x-2x+10)/(x²-25)  * (x²-25)/(2x²+x-6)=

=(x²+4x+4)/(2x²+x-6) =(x+2)²/(2x+3)(x+2)=(x+2)/(2x+3)



[(2x²-2x-17)/(x²-10x+21) -(x+1)/(x-7)] : 1/(x²-9)=
=[(2x²-2x-17)/(x-7)(x-3)) -(x+1)/(x-7)] : 1/(x+3)(x-3)=
=(2x²-2x-17-x²+3x-x+3)/(x-7)(x-3) * (x+3)(x-3)=
=(x²-14)/(x-7) * (x+3)=(x+√7)(x-√7)/(x-7)
x≠7