Problem 61 - Intermediate Algebra

Question

Simplify each numerical expression. $$ 16-18+19-[14-22-(31-41)] $$

Step-by-Step Solution

Answer

The simplified expression is 15.

Step 1: Simplify Inside the Parentheses

Start with the innermost parentheses. Inside \(31 - 41\), calculate \(31 - 41 = -10\). Substitute back to get: \[16 - 18 + 19 - [14 - 22 - (-10)]]\].

Step 2: Simplify Inside the Brackets

Now, handle the brackets. Inside \[14 - 22 - (-10)\], calculate \(14 - 22 = -8\), and then \(-8 - (-10) = -8 + 10 = 2\). Substitute back to get: \[16 - 18 + 19 - 2\].

Step 3: Perform Addition and Subtraction

Start from left to right: \16 - 18 = -2\. Next, \(-2 + 19 = 17\). Finally, \17 - 2 = 15\.

Key Concepts

Order of Operations

When simplifying numerical expressions such as \(16-18+19-[14-22-(31-41)]\), it's crucial to follow the specific sequence of mathematical operations, known as the Order of Operations. This set of rules determines which operations to perform first to correctly simplify or evaluate expressions. Here's a simple breakdown:

• Parentheses: Always start by resolving expressions inside parentheses. If there are nested parentheses, begin with the innermost one.
• Exponents: Next, deal with exponents (not applicable in this case).
• Multiplication and Division: Then, perform multiplication and division from left to right (also not applicable here).
• Addition and Subtraction: Finally, perform addition and subtraction from left to right.

Using this order helps us avoid confusion and errors. In our example, we tackled the innermost parentheses first, then moved toward the outer operations until the expression was simplified.

Arithmetic Operations

Arithmetic operations form the backbone of mathematical calculations, including addition, subtraction, multiplication, and division. In simplifying expressions, we predominantly deal with addition and subtraction. These operations, albeit simple, have specific rules to follow.

Subtracting a number is the same as adding its negative. For instance, in \(16 - 18 + 19 - 2\), each subtraction can be seen as adding a negative equivalent:

• \(16 - 18\) becomes \(16 + (-18)\).
• \(19 - 2\) becomes \(19 + (-2)\).

This perspective can simplify calculations by treating all operations as additions, thus streamlining the process. These operations should always follow the left-to-right sequence once parentheses and multiplication have been addressed, ensuring that we maintain the correct value throughout the problem.

Nested Parentheses

Nested parentheses, or brackets within brackets, can make an expression look more complex but are straightforward to manage by breaking them down one level at a time. In the expression \(16-18+19-[14-22-(31-41)]\), resolving the innermost parentheses first is essential.

Start with the operation inside the deepest layer:

• Calculate \(31-41\) to get \(-10\).
• Replace this value back into the expression, simplifying one layer at a time.

Next, resolve the bracket following the regular order of operations. This prioritization ensures we correctly simplify each component serially, avoiding errors or oversight. As we saw in the original step-by-step solution, this systematic approach simplifies seemingly complicated problems into manageable steps.