2.k=+ 1 or k=- 1.

3. Answer: (x-4) * (3-x)/(x-4)+(x-4) *1/(4-x) = x-4.

3-x+(- 1)=x-4

2x=6

x=3

4. Answer: Multiply both sides of the equation by (x+2)(x- 1) at the same time, and you can get (x-1) * (x-1)-x * (x+2) = m, and you can get x = (1- 0). 0, m > can be solved; 1

5. A: I don't quite understand this question.

6. answer: x-4/x-3-m-4=m/3-x, and both sides can be multiplied by (x-3) to get x-4-(m-4)(x-3)=-m, (5-m) x+4m- 16.

So x=( 16-4m)/(5-m), and if x has no solution, m=5.

7. A: Sorry for the late answer.