First you have to put like terms together:
bf+af+be+ae
Now you factor the first two terms and then the two last terms:
f(b+a)+e(b+a)
Now you factor even further. By putting what is in parentheses by what is outside the parentheses:
(b+a)(f+e)
What you got is correct as mine is too. I hope this formula helps for future problems:
ax+bx+ac+bc=x(a+b)+c(a+b)
=(a+b)(x+c)
