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# Algebra

Below are examples expressions for a variable. I need to explain my problem and answer just like the examples below, please give me a few problems to explain just like the samples below thanks...

A mathematical expression is similar to a phrase or fragment of a sentence. An expression has no subject and no verb or relation symbol such as '=' (is equal to) or '<' (is less than) or '>' (is greater than)

Examples:

Four smaller than a number ... n - 4
Five times a number ... 5n = 5 ? n = 5 (n) = (5) (n)

We cannot solve an expression for a variable. If we are given a value to substitute for the variable, we can simplify or evaluate the expression.

Examples:

Substitute 13 for 'n' and simplify or evaluate the expressions.

n - 4 = 13 - 4 = 9

5n = 5 g 13 = 65

An equation is similar to a complete sentence. It has a subject and verb, and is a complete idea. Mathematical sentences or statements are called equations (=) and inequalities (<, £, >, ³). The relation symbols are the verbs of the sentences.

Examples:

Ten is six less than a number ... 10 = n - 6

Seven times a number is equal to twenty-eight ... 7n = 28

We can solve an equation for a variable ... finding the numerical value that makes the sentence or equation a true statement.

Example:

Solve for n: 10 = n - 6

10 = n - 6 ... We always write the original problem when we start
n = 10 + 6
n = 16 ... This means that n = 16 makes the original equation a true statement

Check:

10 = n - 6
10 = 16 - 6
10 = 10 ... True Statement

Example:

Solve for n: 7n = 28

7n = 28
n = 28 ¸ 7
n = 4 ... This means that n = 4 makes the original equation a true statement

Check:

7n = 28
7 g 4 = 28
28 = 28 ... True Statement

#### Solution Preview

1. Write mathematical expressions for following phrases:

(a) Five more than a number
(b) Eight times a number
(c) Six less than seven times a number
(d) Five more than eleven times a ...

#### Solution Summary

This solution is comprised of a detailed explanation to solve problems.

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