Calculations involving surds

Hello, I don’t know how they got the answer to question 3. Please help me understand.
IMG_20230204_114438
IMG_20230204_114954

Kia
this is another good question which requires the use of “indice rules”
5 Feb 23.docx (91.1 KB)
I have attached the answer on a word document
Please let me know if you need any more help
regards