Respuesta :

Answer:

{10, -8} (A)

Step-by-step explanation:

Since it is absolute value, n-1 can equal both 9 or -9.

First you solve for n-1=9.  That would make n=10

Then you solve for n-1= -9 .That would make n=-8

Answer:

A) {10, -8}

Step-by-step explanation:

Since it is absolute value, you must split it into two equations:

n-1=9

n-1=-9

Now solve for n in both equations

n=10

n=-8

Therefore, the answer is A