I dont understand hou to do this.... help

Well, I'll solve one of them.

1. \(6x+4x-6=24+9x, 10x-6=24+9x, x=30\), so one solution.

Remember infinite solutions, 0=0, etc.

Don't be so lazy. TYPE just one of these questions in, lean from the answer, and do the others yourself.

You won't learn anything from copying all of other peoples answers. 

b) 25 - 4x  = 15- 3x + 10 - x   simplify

25 - 4x = 25 - 4x

Same expressions on both sides will give us infinite solutions for  x

 c) 4x + 8  = 2x + 7 + 2x  - 20    simplify

4x + 8 =  4x - 13       subtract 4x from both sides

8  = -13     absurd answer  means that no solutions exist.....