Does anyone understand these two problems:

Problem 1:

https://webwork.uncc.edu/webwork2_fi...36fe4c71e1.png (hint: https://webwork.uncc.edu/webwork2_fi...29a8a6dbf1.png )

Problem 2:

https://webwork.uncc.edu/webwork2_fi...f72c808921.png

help please?

for 1, I got -2k

& for 2, I got 3

which were wrong