Question

A=\(\dfrac{x^2+2x}{2x+10}+\dfrac{x-5}{x}+\dfrac{50-5x}{2x\left(x+5\right)}\)

a) Tìm x để A xác định 

b) Rút gọn A 

c) Tìm x để A=1

Mấy pro toán chỉ mình nha

 

Answer 1

ok 

 

Answer 2

\(a,ĐK:x\ne0;x\ne-5\\ b,A=\dfrac{x^3+2x^2+2x^2-50+50-5x}{2x\left(x+5\right)}=\dfrac{x^3+4x^2-5x}{2x\left(x+5\right)}\\ A=\dfrac{x^2+4x-5}{2\left(x+5\right)}=\dfrac{\left(x+5\right)\left(x-1\right)}{2\left(x+5\right)}=\dfrac{x-1}{2}\\ c,A=1\Leftrightarrow x-1=2\Leftrightarrow x=3\left(tm\right)\)

Answer 3

\(A=\dfrac{x^2+2x}{2\left(x+5\right)}+\dfrac{x-5}{x}+\dfrac{50-5x}{2x\left(x+5\right)}\\ ĐKXĐ:\left\{{}\begin{matrix}x\ne0\\x+5\ne0\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x\ne0\\x\ne-5\end{matrix}\right.\)

Answer 4

b: \(A=\dfrac{x^3+2x^2+2x^2-50+50-5x}{2x\left(x+5\right)}=\dfrac{x^3+4x^2-5x}{2x\left(x+5\right)}=\dfrac{x\left(x+5\right)\left(x-1\right)}{2x\left(x+5\right)}=\dfrac{x-1}{2}\)