Respuesta:
1.
[tex]\frac{2x-2}{x^2-1}+\frac{3x^2-1}{x^2-1}-\frac{x+1}{x^2-1}\\\\=\frac{2x-2+3x^2-1-\left(x+1\right)}{x^2-1}\\\\=\frac{3x^2+x-4}{x^2-1}\\\\=\frac{\left(x-1\right)\left(3x+4\right)}{x^2-1}\\\\=\frac{\left(x-1\right)\left(3x+4\right)}{x^2-1}\\\\=\frac{3x+4}{x+1}[/tex]
2.
[tex]\frac{3x}{x^2-1}+\frac{2x}{x+1}-\frac{5}{x-1}\\\\=\frac{3x}{\left(x+1\right)\left(x-1\right)}+\frac{2x}{x+1}-\frac{5}{x-1}\\\\=\frac{3x}{\left(x+1\right)\left(x-1\right)}+\frac{2x\left(x-1\right)}{\left(x+1\right)\left(x-1\right)}-\frac{5\left(x+1\right)}{\left(x-1\right)\left(x+1\right)}\\\\=\frac{3x+2x\left(x-1\right)-5\left(x+1\right)}{\left(x+1\right)\left(x-1\right)}\\\\=\frac{2x^2-4x-5}{\left(x+1\right)\left(x-1\right)}[/tex]
3.
[tex]\frac{2}{x}+\frac{3}{x+1}-\frac{5x-6}{x^3+x^2}\\\\=\frac{2}{x}+\frac{3}{x+1}-\frac{5x-6}{x^2\left(x+1\right)}\\\\=\frac{2x\left(x+1\right)}{x^2\left(x+1\right)}+\frac{3x^2}{\left(x+1\right)x^2}-\frac{5x-6}{x^2\left(x+1\right)}\\\\=\frac{2x\left(x+1\right)+3x^2-\left(5x-6\right)}{x^2\left(x+1\right)}\\\\=\frac{5x^2-3x+6}{x^2\left(x+1\right)}[/tex]