Question 1.1. State a conjunction or disjunction equivalent to the open sentence |a – 9| ≤ 4.
a – 9 ≥ 4 and a – 9 ≤ –4
a – 9 ≤ 4 or a – 9 ≥ –4
a – 9 ≤ 4 and a – 9 ≤ –4
a – 9 ≤ 4 and a – 9 ≥ –4

Question

Question 1.1. State a conjunction or disjunction equivalent to the open sentence |a – 9| ≤ 4.
       a – 9 ≥ 4 and a – 9 ≤ –4
       a – 9 ≤ 4 or a – 9 ≥ –4
       a – 9 ≤ 4 and a – 9 ≤ –4
       a – 9 ≤ 4 and a – 9 ≥ –4

perl · Answer

| x | < = a   has the solution   -a <= x <= a

anonymous · Answer

?

perl · Answer

that is a general form for the solution

perl · Answer

plug in a-9 for x

perl · Answer

In general  
| x | < = k, where k>0,  has the solution -k <= x <= k

perl · Answer

| a - 9 | <= 4
is equivalent to 
-4 <= a - 9 <= 4