Question

Write an absolute value inequality to represent each situation.

Answer 1

Answer:

║ x - 231 ║ ≤ 459

Step-by-step explanation:

Since we have 228 ft below sea level, this is x' = -228 ft. Also,  we have 690 ft above sea level, this is x" = 690 ft.

Since x is our elevation in feet, x ranges from -228 ≤ x ≤ 690.

To write an absolute value equation for x, we first take the average of the two values for the ranges to obtain the ideal value of x.

So, ideal value = [690 + (-228)]/2 = 462/2 = 231.

We also find the tolerance by taking the difference of both values and dividing by 2. So tolerance = [690 - (-228)]/2 =  [690 + 228)]/2 = 918/2 = 459.

Subtracting 231 from each value of the inequality we have

-228 - 231 ≤ x - 231 ≤ 690 - 231

-459 ≤ x - 231 ≤ 459

Since we have in magnitude the values on the left and right side of the inequality,

So ║ x - 231 ║ ≤ 459