student

I've only done part b
I have done this as a rough copy attachment.
I am notorious for making stupid mistakes but if you can follow at all it should show you how they are done.
If you would like me to explain better feel free to ask

Ajeng's problem .jpg

You can just do x^3 + y^3 using the expansion that maybe you should know (x+y)*(x^2 - x*y + y^2) and then do the substitutions
I got 20* root7
It took me just 4 lines of working

If I have helped but you would like more information let me know.