Absolute Value Scenarios
CONCEPTS
Tips
• Write out a series of numbers that fits the scenario criteria
• Write down all equations and try to insert the variables from the question into the equation
PRACTICE PROBLEMS
Question 1 For some positive integer k, the sum of the absolute values of all the integers from -k through k is 12. What is the value of k?
-- Answer -- 3
12/2 = 6, 1 + 2 + 3 = 6
|-3| + |-2| + |-1| + |0| + |1| + |2| + |3| = 3 + 2 + 1 + 0 + 1 + 2 + 3 = 12
k = 3
Question 2 Which expression is equivalent to | a - b - c |?
| a + b + c |
| a + b - c |
| a - b + c |
| -a + b + c |
| -a - b - c |
-- Answer -- | -a + b + c |
Because the absolute value equation |x| = |-x| is always true, | a - b - c | = | -a + b + c |
ACT PRACTICE PROBLEMS