The graph of f(x) = 2x + 4 shifts six units to the right when it is replaced with the graph of f(x) = 2x − k. what is the value of k?

I believe that it should be 2.

+4 means it is shifted 4 units to the left from the y axis. And -2 means it shifts 2 units to the right from the y axis. So the shift of four would leave it at -4 for the x axis and the shift of four would leave you at positive 2 for the x axis. The difference of -4 and two is six, proving that your answer is 2.

Sorry if this is wrong or doesn’t make sense.

Cthe residual plot for model 1 has a non random pattern and is a good fit for the data