Question

f(x)= e^{-x^2/2}

Im at the second derivative where I dont know how it got from F"(x)= e^-x^2/2 * (-1) * (-x) * e^(-x^2/2)

there was a point in the middle where the above equation wasmerged into this: -2e^-x^2/2 + 2x , i understand that but dontunderstand how it came to be the term below

to : e^-x^2/2 (-1+x^2)

thanks