7[ excluding {0, 1, 2}(A itself)]

7[ Delete Empty Set]

Two: non-right triangle [triangle is an acute triangle or an obtuse triangle, which exists in both A and B, but the right triangle in the triangle is not among them, so the set of A and B is a non-right triangle]

Three: {x|x belongs to R and x is less than or equal to 3}[ The complement set of real numbers except A is the set of numbers in real numbers that do not belong to A]

Four: 2[f( 1) equals 1 2+| 1-2 | equals1| equals 1+0 equals 2].

Five: {x|x belongs to R and X is greater than or equal to -4 and X is not equal to -2}[ To make Y meaningful, X should be a real number, so the denominator is not 0, so X is not equal to -2. To make (x+4) under the root sign meaningful [I think the problem is this], X+4 should be greater than or equal to 0, so X should be greater than or equal to -4].

Six: {x|x belongs to R and X is greater than or equal to 2} [Like the five questions, M is a real number set greater than or equal to 2, and N is a relationship set with Y, so Y is a non-negative real number set, so the intersection of M and N is a real number set greater than or equal to 2].