Answer:
65
Step-by-step explanation:
None of the values in the set {70, 90, 100} will make the equation x - 30 = 65 true.
Let's try substituting each value into the equation:
If x = 70, then 70 - 30 = 40 ≠ 65
If x = 90, then 90 - 30 = 60 ≠ 65
If x = 100, then 100 - 30 = 70 ≠ 65
Since none of the substitutions result in 65, there is no value of x within the set {70, 90, 100} that validates the equation.