Register Now

Login

Lost Password

Lost your password? Please enter your email address. You will receive a link and will create a new password via email.

222-9+11+12:2*14+14 = ? ( )

Toán Lớp 8: Câu hỏi cuối cùng trc khi off acc nì ^^ ($\frac{x}{x²-25}$ – $\frac{x-5}{x²+5x}$ ): $\frac{2x-5}{x²+5x}$ + $\frac{x}{5-x}$

Toán Lớp 8: Câu hỏi cuối cùng trc khi off acc nì ^^
($\frac{x}{x²-25}$ – $\frac{x-5}{x²+5x}$ ): $\frac{2x-5}{x²+5x}$ + $\frac{x}{5-x}$

Comments ( 2 )

  1. U\omegaU         
    Giải đáp:
    =-1
    Lời giải và giải thích chi tiết:
    =\frac{x.x-(x-5)²}{x(x-5)(x+5)} .\frac{x²+5x}{2x-5} +\frac{x}{5-x}
    =\frac{10x-25}{x(x-5)(x+5)} .\frac{x(x+5)}{2x-5} +\frac{x}{5-x}
    =\frac{5}{x-5} +\frac{-x}{x-5}
    =\frac{5-x}{x-5}
    =-1

  2. $\\$
    (x/(x^2-25)-(x-5)/(x^2+5x)):(2x-5)/(x^2+5x)+x/(5-x)(x\ne 0, x\ne 5, x\ne -5)
    =(x/((x-5)(x+5))-(x-5)/(x(x+5)) ).(x^2+5x)/(2x-5)+x/(5-x)
    =(x^2/(x(x-5)(x+5)) – (x^2-10x+25)/(x(x-5)(x+5)) ).(x^2+5x)/(2x-5)+x/(5-x)
    = (x^2 – x^2+10x-25)/(x(x-5)(x+5)) . (x(x+5))/(2x-5) + x/(5-x)
    = (5(2x-5))/(x-5) . 1/(2x-5)+x/(5-x)
    = 5/(x-5) – x/(x-5)
    =(5-x)/(x-5)
    =(-(x-5))/(x-5)
    =-1

Leave a reply

222-9+11+12:2*14+14 = ? ( )