Answer:
The required absolute inequality is |x - 78| ≤ 20.
Step-by-step explanation:
Consider the provided information.
Let $x is monthly charge.
The monthly charges for a basic cable plan = $78
it is given that it could differ by as much as $20
So, the maximum charges can be $78 + $20,
And, the minimum charges can be $78 - $20,
The value of x is lies from $78 - $20 to $78 + $20
Which can be written as:
78 - 20 ≤ x and x ≤ 78 + 20
-20 ≤ x - 78 and x - 78 ≤ 20
Change the sign of inequality if multiplying both side by minus.
20 ≥ -(x - 78) and x - 78 ≤ 20
⇒ |x - 78| ≤ 20
Thus, the required absolute inequality is |x - 78| ≤ 20.
