The correct answer is:
x < 17.89 or x > 18.61 because |x – 18.25| > 0.36 .
Step-by-step explanation:
We know that the target weight is 18.25. We also know that to be accepted, the weight of each pack must be within 0.36 of this target weight. The packs can be up to 0.36 more than or up to 0.36 less than the target weight; for this reason, we use an absolute value equation:
|x-18.25| ≤ 0.36
However, we are concerned with the weights of the packs that are rejected. These will be more than 0.36 different from the target weight:
|x-18.25| > 0.36
To solve this, we consider the positive and negative values of 0.36 (since it is an absolute value equation). Remember the rules of inequalities; when we change the sign of the answer, we change the inequality sign as well:
x - 18.25 > 0.36 or x - 18.25 < -0.36
To solve each of these, add 18.25 to each side:
x - 18.25 + 18.25 > 0.36 + 18.25 or x - 18.25 + 18.25 < -0.36 + 18.25
x > 18.61 or x < 17.89
This means the correct choice is the first one.