<p>The weights of 10 bags of apples range from 2.75 pounds to 3.15 pounds. If w is the weight, in pounds, of one of these bags, which of the following must be true?</p>
<p>it's | w 2.95 | <= 0.2 </p>
<p>but why do you have to subtract 2.95 to get the answer</p>
<p>2.75 2.95 <= w 2.95 <= 3.15 2.95</p>
<p>you sure your subtracting? The reason why | w 2.95 | <= 0.2 works is because 2.95 has an equal distance away from 2.75 and 3.15. This distance is 0.2. Now your question on how it works:
Put the equation in your own words. The pounds of apples can be w => 2.75 or w <= 3.15. So now solve the |w-2.95|<=0.2.
1) -|w-2.95| <= 0.2 ; w-2.95 => -0.2 ; w => 2.75
2) |w-2.95| <= 0.2 ; w - 2.95 <= 0.2 ; w <= 3.15</p>