(i) For all even integers x, x2 is also even.
The quantifier is “For All”.
The negation of the statement is-
“There exists an even integer x such that x2 is not even”.
(ii) There exists a number which is a multiple of 6 and 9.
The quantifier is “There exists”.
The negation of the statement is-
“There does not exist a number which is a multiple of both 6 and 9”.