Hey!
First, let's write the problem.

We know that,

, so let's apply that

We have to add,


We know that

, so let's apply that.

Subtract.

Our final answer would be 7!Thanks!
-TetraFish
Answer:
111,117,177,777,771,711,717,171
Step-by-step explanation:
The answer is n=5. I worked it out
KX = x+4 so solve for k.
Divide both sides of the equation by x and you get K=4.
Plug it in, and you get (4)(7)=28
Your answer is 28.