Problem 68 - Elementary Algebra Within Reach

Question

In Exercises \(63-68\), simplify the expression. $$ 7(-10 x) $$

Step-by-Step Solution

Answer

The simplified expression is -70x

Step 1: Apply the relevant algebraic rules

Use properties of exponents, radicals, or algebraic identities to simplify the expression.

Step 2: State the simplified result

The simplified expression is The simplified expression is -70x.

Key Concepts

Multiplication Operation

When you come across a multiplication operation in elementary algebra, it fundamentally means that you must combine numbers or variables by the process of repeated addition. For example, if you have the expression \( 7(-10 x) \), you are asked to multiply 7 by \( -10x \). This might appear daunting at first, but with practice, you'll see it's quite direct.

Multiplication is commutative, which means the order in which you multiply the numbers does not change the result. Thus, \( 7(-10x) \) is equivalent to \( (-10x)(7) \). To simplify such an expression, multiply the numerical values together and then attach the variable part of the expression. Here, \( 7 \times -10 \) equals -70, and you retain the \( x \) to get \( -70x \).

Remember, multiplying a positive number by a negative one always gives a negative result. Thus, a positive 7 multiplied by a negative \( -10x \) will result in \( -70x \), not \( 70x \) which would have been the case had the sign of \( 10x \) been positive.

Algebraic Expressions

Algebraic expressions are the backbone of algebra and include numbers, variables, and arithmetic operations. They represent values that may change; for instance, in \(7(-10x)\), \(x\) is the variable that can have various values. Adequately simplifying algebraic expressions is essential as they form the basis for solving equations.

An important thing to note while simplifying is to always perform operations in the correct order. Here, you have only multiplication, so things are straightforward. However, if your expression includes a mix of addition, subtraction, multiplication, and division, remember to follow the order of operations, often given by the acronym PEMDAS (Parentheses, Exponents, Multiplication and Division, Addition and Subtraction).

The use of variables allows algebraic expressions to model real-world situations dynamically, making them a powerful tool in mathematics. Also, grasping the art of manipulating these expressions is key to success in algebra.

Elementary Algebra

Elementary algebra is your starting line in the race of understanding higher maths. It lays the foundation for more complex topics and aids in developing critical reasoning and problem-solving skills. In elementary algebra, we begin to use symbols and letters to represent numbers.

In the context of the given exercise, elementary algebra teaches us how to simplify expressions before tackling equations. The expression \( 7(-10 x) \) is an example of this. While it may seem elementary, understanding how to simplify this requires knowledge of basic algebraic operations and principles. The purpose of simplifying is to make the expression as easy to understand and as straightforward as possible.

Simplification involves reducing the expression to its most basic form while adhering to mathematical rules. This process often involves combining like terms, using distributive properties, and eliminating unnecessary parentheses. It's not just about making the equation look neater; it's about understanding the structure and relationship between the parts of the mathematical statement.