Please help me with 1,2,3,4,5,6,7,8,9 tell me how u get it and the answer please I really need help

What's the difference between: x≥0 and nonnegative integer. ?

Simplify 4 square root of 2 end root plus 7 square root of 2 end root minus 3 square root of 2 . (1 point) 2 square root of 8 8 square root of 2 8 square root of 6 6 square root of 8

(01.04 lc)multiply 1 over 6 multiplied by negative 1 over 2. negative 1 over 3 negative 1 over 12 1 over 12 1 over 3