Question

A number is more than 9 units from 3.

Answer 1

Answer: It's either -6 or 12. I'm assuming it's 12 because it says "more than."

Step-by-step explanation:

Answer 2

You must account for both the number being more than 9 units smaller than 3 and being more than 9 units larger than 3. To do that, you set the absolute value of the difference between the number and 3 greater than 9.

Let x be the number

|x - 3| > 9

Now solve for x.

Suppose x - 3 is positive. Then

x - 3 > 9 ⇒ x > 12

Suppose x - 3 is negative. Then |x - 3| = -(x - 3) = 3 - x

Then

3 - x > 9 ⇒ x < -6

These are the 2 possibilities.


Hope this helps