Задача Задача №3787481
А
А
Сверь числа и знаки с фото.
\[\frac{5}{x-7}-\frac{2}{x}-\frac{3x}{x^2-49}+\frac{21}{49-x^2}=\]
\[ \frac{5}{x-7}-\frac{2}{x}-\frac{3x}{x^2-49}+\frac{21}{49-x^2} =\frac{5}{x-7}-\frac{2}{x}-\frac{3x+21}{x^2-49} \] \[ =\frac{5}{x-7}-\frac{3}{x-7}-\frac{2}{x} =\frac{14}{x(x-7)}. \]
\[ \boxed{\frac{14}{x(x-7)}},\qquad x\ne0,\ x\ne\pm7. \]