∫ e − x d x , u = − x u = − x d u = − d x {\displaystyle {\begin{aligned}&\int {e^{-x}}dx,\quad u=-x\\[2ex]&u=-x\\[2ex]&du=-dx\\[2ex]\end{aligned}}}
∫ e − x d x = − ∫ e u d u = − e u + C = − e − x + C {\displaystyle \int {e^{-x}}dx=-\int {e^{u}}du=-e^{u}+C=-e^{-x}+C}
![{\displaystyle {\begin{aligned}&\int {e^{-x}}dx,\quad u=-x\\[2ex]&u=-x\\[2ex]&du=-dx\\[2ex]\end{aligned}}}](https://en.wikipedia.org/api/rest_v1/media/math/render/svg/6e256caafce417840d30b15cc0dc0acbf3e56a1e)
