5.) 4√x Explanation: put the 8 and the 2x in the same root, √8(2x) then multiply the 2 with the 8 to get √16x then simplify the radical by getting 2^2 times √x and 2 squared is 4 √x giving you that answer
6.) x/3 Explanation: combine both to get √3x/18(2x/3) cancel out the 3’s to get √x/18(2x) reduce the 18 and 2 as the greatest common factor is nine so decide by two to get √x/9(x) the 2 x’s become squares, √x^2/9 after calculating the square root you get x/3.
7. (It’s a long answer lol) ^4 √6075x^7+9720x^6+3888x^5 / 3x
This may be confusing but I hope it helps! Have a good day :)