Answer:
C and D
Explanation:
You can tell if equations have no solution if the variables on both sides of the equation are the same.
Choice C is 10+6x=15+9x-3x. You would combine 9x and -3x, turning the equation into 10+6x=15+6x. Since there is a 6x on both sides, Choice C would have no solution.
The same for Choice D. When you simplify everything there is a 3x on both sides, so it would have no solution.