Chapter 2: Problem 36
For Exercises \(1-74,\) simplify. $$|21 \div(-3)+12|$$
Short Answer
Expert verified
Answer: 5
Step by step solution
01
Perform Division
First, perform the division operation inside the absolute value: \(21 \div(-3)\)
\(21 \div(-3) = -7\)
Now the expression becomes: \(|-7 + 12|\)
02
Perform Addition
Next, perform the addition operation inside the absolute value: \(-7 + 12\)
\(-7+12 = 5\)
Now the expression becomes: \(|5|\)
03
Compute Absolute Value
Finally, we need to compute the absolute value of the result: \(|5|\)
As 5 is a positive number, its absolute value is equal to its value: \(|5| = 5\)
So, the simplified expression is: $$5$$
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Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Division in Algebra
Division in algebra is a key mathematical operation. It involves dividing one quantity by another. If we look at the exercise, we divide 21 by -3, expressed as \(21 \div (-3)\). This division leads to \(-7\).
This step is crucial for simplifying algebraic expressions, helping to break down complex problems into simpler parts.
Here are some important points to remember about division in algebra:
This step is crucial for simplifying algebraic expressions, helping to break down complex problems into simpler parts.
Here are some important points to remember about division in algebra:
- Sign Rules: When dividing, remember that a positive number divided by a negative number results in a negative number.
- Inverse Operation: Division is the inverse of multiplication. So, \(a \div b\) is like multiplying \(a\) by the reciprocal of \(b\), which is \(1/b\).
Absolute Value
The absolute value of a number is its distance from zero on a number line, regardless of direction. In simpler terms, it turns any number into its non-negative version.
Looking at the exercise, after performing division and addition, we have the expression \(|5|\). Since 5 is already positive, its absolute value is 5.
Some key points about absolute value:
Looking at the exercise, after performing division and addition, we have the expression \(|5|\). Since 5 is already positive, its absolute value is 5.
Some key points about absolute value:
- Non-Negativity: The absolute value of any number is always non-negative. For instance, \(|-3| = 3\) and \(|3| = 3\).
- Functionality: Think of absolute value as a function that outputs the magnitude of the input without its sign.
Order of Operations
The order of operations is a fundamental concept in mathematics that dictates the sequence in which operations should be performed to accurately solve expressions. In our exercise, this principle guides us in simplifying \(|21 \div(-3)+12|\).
Follow these steps to ensure accuracy:
Follow these steps to ensure accuracy:
- Parentheses: Perform operations inside parentheses first. However, our expression uses absolute value bars which function similarly in terms of hierarchy order.
- Exponents: Calculate any exponents second, though none are present in this case.
- Multiplication and Division: These are handled next, and from left to right. In the exercise, division was the first step: \(21 \div(-3)\).
- Addition and Subtraction: Finally, perform addition and subtraction from left to right. Here, \(-7 + 12\) was performed after the division.