Question

Which number is NOT in the solution set of x - 9 > 3?

a) 11
b) 13
c) 1
d) 15

Answer 1

To find the number NOT in the solution set, solve the given inequality x - 9 > 3 by adding 9 to both sides, and simplify to find x > 12. The number NOT in the solution set is 1.

Step-by-step explanation:

The given inequality is x - 9 > 3. To find the numbers that are NOT in the solution set, we need to determine which values of x make the inequality false. Let's solve the inequality:

1. Start with x - 9 > 3.
2. Add 9 to both sides of the inequality: x - 9 + 9 > 3 + 9.
3. Simplify: x > 12.

The solution set of the inequality is all numbers greater than 12. Therefore, the number NOT in the solution set is 1 (option c).