
David W. answered 05/14/15
Tutor
4.7
(90)
Experienced Prof
Hey, Jack! Moaning won't help. "When the going gets tough, the tough get going!"
Let's read the problem: The absolute value of the quantity x minus 20 is less than 0.75
Absolute values cannot be negative.
The goal of this problem is to solve for x (alone) by putting all the numbers on the other side of the inequality.
So, here goes:
The quantity (x-20) is between -0.75 and 0.75 on the number line, right? (small numbers on either side of 0)
-0.75 < (x-20) < 0.75
This is two situations combined and both have to be true.
- 0.75 < x -20 and x-20 < 0.75
With inequalities, we can add the same amount to both sides and keep the same inequality.
19,25 < x and x < 20.75
Now, I'd encourage to draw that interval on a number line and try a value inside that range. For example, x=20 is in that line segment, so is the absolute value of (20-20) less than 0.75? YES !