We all have studied absolute value in our schools but with time it became a bit complex. Down the line what we basically learnt in absolute value is:
|positive| = positive
As well as,
|negative| = positive
But, GMAT is never going to ask you such an easy question.
In GMAT Exam, you can expect the following types of questions:
- |3x + 8| = 42
So, 3x + 8 = 42 or, 3x + 8 = -42
3x = 34 or, 3x = -50
x = 11.333 or, x = -16.666
Let’s solve some more complex questions and see what GMAT actually tests.
1. Find the value of x in:
|x + 2| + |x – 3| = |2x + 3|
If we suddenly look at this question, we won’t have any idea of solving it.
So, let’s solve it step-by-step.
- There is a variable in this question.
- When a variable is here, we can simply plug-in any number at its place.
- Value of x is one of the given options. So, let’s substitute these options and check which one fulfills the constraints.
|-5 + 2| + |-5 – 3| = |2 (-5) + 3|
|-2 – 2| + |-2 + 3| = |2 (-2) + 3|
|1 + 2| + |1 – 3| = |21+3|
So, C is the answer.
Tip: Solving a problem in traditional way can eat-up a lot of your time. So, try different approaches.
- If m + |m| = 0, then m is,
Let’s check each possibility,
Case1. m is positive.
|m| = m
So, m + |m| = 0
m + m = 0
So this case is not possible.
Case2. m is 0
So, |m| = 0
0 + 0 = 0
So this is a possible case
Case3. m is negative.
|m| = -m
|m| + m = 0
-m + m = 0
So, m is either 0 or negative.