Hey homalina.
Can you show what you have tried already? What you are thinking? You need to make an attempt yourself before you get specific advice and suggestions.
jawabe soal 6.pdf - This is what I have done for the first part - and for the second part I know that I am supposed to square the whole of the second part of the question and then I will get 1/the exact denominator of the second part of the question but I am not sure if thats correct and the third part I just dont have a clue...
Thanks!