khó gì fan gao bạc
a,
ĐKXĐ : \(\hept{\begin{cases}x\ne3\\x\ne-1\end{cases}}\)
\(\frac{x}{2\left(x-3\right)}+\frac{x}{2\left(x+1\right)}=\frac{2x}{\left(x+1\right)\left(x-3\right)}\)
\(\frac{x\left(x+1\right)}{2\left(x-3\right)\left(x+1\right)}+\frac{x\left(x-3\right)}{2\left(x+1\right)\left(x-3\right)}=\frac{4x}{2\left(x+1\right)\left(x-3\right)}\)
\(x\left(x+1\right)+x\left(x-3\right)=4x\)
\(x^2+x+x^2-3x=4x\)
\(2x^2-2x=4x\)
\(2x^2-2x-4x=0\)
\(2x^2-6x=0\)
\(2x\left(x-3\right)=0\)
\(2x=0\Leftrightarrow x=0\)
hoặc
\(x-3=0\Leftrightarrow x=3\)
Theo ĐKXĐ : x = 0
b,
ĐKXĐ : \(x\ne\pm4\)
\(\frac{5+76}{x^2-16}=\frac{2x-1}{x+4}-\frac{3x-1}{4-x}\)
\(\frac{81}{x^2-16}=\frac{2x-1}{x+4}-\frac{3x-1}{4-x}\)
\(\frac{81}{\left(x+4\right)\left(x-4\right)}=\frac{2x-1}{x+4}-\frac{3x-1}{4-x}\)
\(\frac{81\left(4-x\right)}{\left(x+4\right)\left(x-4\right)\left(4-x\right)}=\frac{\left(2x-1\right)\left(4-x\right)\left(x-4\right)}{\left(x+4\right)\left(4-x\right)\left(x-4\right)}-\frac{\left(3x-1\right)\left(x+4\right)\left(x-4\right)}{\left(4-x\right)\left(x+4\right)\left(x-4\right)}\)
\(81\left(4-x\right)=\left(2x-1\right)\left(4-x\right)\left(x-4\right)-\left(3x-1\right)\left(x+4\right)\left(x-4\right)\)
\(324-81x=18x^2-5x^3+8x\)
\(324-81x-18x^2+5x^3-8x=0\)
\(\left(5x^2+2x-81\right)\left(x-4\right)=0\)
\(5x^2+2x-81=0\)
=> vô nghiệm
\(x-4=0\Leftrightarrow x=4\)
Theo ĐKXĐ : vô nghiệm
