What is the steps on how to solve...

-2(7 - n) + 4

First:  use the distributive property:  -2(7 - n)  =  (-2)(7) - (-2)(n)  =  -14 + 2n:

-14 + 2n + 4

Now:  add like terms:  -14 + 4  =  -10

-10 + 2n