simpilify (2e -2f)(2f +8)=

Remember the FOIL rule when doing problems like this.

First product: 4ef
Outside product: 16e
Inside product: -4f^2
Last product: -16f

Finally, add up those four terms. Try it!
If you factor out the 4, you get
4(ef + 4e -f^2 -4f)