Answer:
3
Explanation:
The function is undefined when its denominator is zero. The value of x that makes the function undefined is the solution to
10x -30 = 0
x - 3 = 0 . . . . . divide by 10
x = 3 . . . . . . . . add 3
The value of x that is not in the domain of the function is x=3. The function is not defined for that value of x.