Solve LaTeX:  \displaystyle \frac{4}{x - 7}=- \frac{6}{x + 10} .

The LCD is LaTeX:  \displaystyle \left(x - 7\right) \left(x + 10\right) . Multiplying by the LCD to clear the fractions gives LaTeX:  \displaystyle 4 x + 40 = 42 - 6 x . Isloating LaTeX:  \displaystyle x gives LaTeX:  \displaystyle x = \frac{1}{5} .