Solve $LaTeX: \displaystyle \frac{3}{x + 2}=- \frac{4}{x - 1}$ .

The LCD is $LaTeX: \displaystyle \left(x - 1\right) \left(x + 2\right)$ . Multiplying by the LCD to clear the fractions gives $LaTeX: \displaystyle 3 x - 3 = - 4 x - 8$ . Isloating $LaTeX: \displaystyle x$ gives $LaTeX: \displaystyle x = - \frac{5}{7}$ .