Don't worry. You're right. The guide is wrong.
It is just a simple revision, but the answer on the guide and my answers are different! So I would appreciate any help, thank you very much :] It would also be great if the method to solving is shown, because whatever I do, the answer is wrong so I wanted to check where I am wrong.(An example of a question too is given in order to get familiar with the question, just in sake. Thankyou)
Eg:- Q. 8^{2/3 }
A. 8 ^{2/3 }= (2^{3})^{2/3 = }2 ^{3x2/3 }= 2^{2 }= 4
Math Question : 16^{-1/2}
My answer: 16^{-1/2} = 1/16^{1/2} = 1/ √16 = 1/4
Answer on the guide: 4
I would appreciate any help, Thank you.