Найдите область определения функции f(x)=(x+2)/(x^2+x-20).

\[f(x) = \frac{x + 2}{x^{2} + x - 20}\]

\[x^{2} + x - 20
eq 0\]

\[D = 1 + 80 = 81\]

\[x_{1} = \frac{- 1 + 9}{2} = 4;\ \ x_{2} = \frac{- 1 - 9}{2} = - 5\]

\[D(y) = ( - \infty; - 5) \cup ( - 5;4) \cup (4; + \infty).\]