Equation 1:

\int_{-\infty}^{+\infty} e^{-a(x+b)^2}dx = \sqrt{\frac{\pi}{a}}

Equation 2:

\int_{-\infty}^{+\infty} e^{-ax^2+bx+x}dx = \sqrt{\frac{\pi}{a}}e^{b^2/{4a} + c}