Algebra - Standard Form

  • Introduction
  • What is Standard Form in Algebra?
  • Algebraic Expressions and Equations in Standard Form
  • Importance of Standard Form
  • Solved Problems
  • Practice Problems
  • Frequently Asked Questions

 

Introduction

Standard form is an important concept in algebra that helps to represent mathematical expressions, equations, and numbers in a comprehensible, systematic, and standardized way. The standard form, its meaning, and its applications in different algebraic contexts are all covered in this article.

 

What is Standard Form in Algebra?

In algebra, standard form refers to a standard and widely acknowledged method of representing numbers, equations, and expressions to improve clarity and ease of computation. This form makes it possible to compare, manipulate, and analyze different mathematical entities effectively. 

The standard form of `3.5\times 10^5` is `350,000`.

 

Algebraic Expressions and Equations in Standard Form

Standard form is required in algebraic expressions to express polynomials in a comprehensive and systematic way. For instance:

 The equation `Ax+By=C`, where `A, B,` and `C` are constants, is frequently used to describe the standard form of a linear equation. The analysis and solution of linear equations are made simpler by using this form.

Standard form rules

Standard form: `Ax+By=C`

  1. `A` cannot be negative
  2. `A` and `B` both not zero
  3. `A, B,` and `C` are integers

Example of a linear equation in standard form: `3x - 5y = 6` 

A polynomial is expressed in standard form by arranging its terms in decreasing order of degree. The term with the highest degree is first and is followed by the other terms in order of decreasing degree. 

For instance: A polynomial of degree `4` can be written in standard form as `3x^4-5x^3-6x^2+9x-10`.

 

Importance of Standard Form

Clarity and Consistency: Standard form gives mathematical statements, equations, and numbers a manner to be represented that is both clear and consistent, which improves mathematical comprehension and comparison.

Effective Comparison: It is simpler to compare and assess numbers and expressions written in standard form. Presenting polynomials and linear equations in standard form in algebraic expressions and equations enables uniform and standardized representations, thus simplifying calculations and analysis.

Solved Problems

Problem `1`:  Solve the following equation for `x`:

`3x - 2y = 8`

Solution: 

The standard form of a linear equation is `Ax + By = C`, where `A, B,` and `C` are integers and `A` is non-negative. The given equation is in standard form with `A = 3, B = -2,` and `C = 8`.

We have: `3x - 2y = 8`

First, to isolate `3x` on the left side, add `2y` to both sides:
`3x = 2y + 8`

Now, divide both sides by `3` to solve for `x`: 
`x = (2y + 8)/3`

 

Problem `2`: Convert the following equation into standard form:

`(2/5)x - (3/4)y = 7/2`

Solution: To express the equation in standard form, we need to clear the fractions and have integers as coefficients for `x` and `y`.

Given equation: `(2/5)x - (3/4)y = 7/2`

Multiply all terms by the least common multiple (LCM) of the denominators (`5` and `4`), which is `20`, to eliminate fractions:
`(20)(2/5)x - (20)(3/4)y = (20)(7/2)`

Now, simplify each term:
`8x - 15y = 70`

Now, the equation is in standard form, with `A = 8, B = -15,` and `C = 70`.

 

Problem `3`: Convert the following equation into standard form:

`y = 3x - 24`

Solution: To express the equation in standard form, we need to have the `x` and `y` terms on one side of the equation.

Given equation: `y = 3x - 24`

Subtract `3x` from both sides of the equation.
`y  - 3x = 3x - 24 - 3x`
`y  - 3x = - 24`

Now, rearrange the terms on the left side to have the `x`-term first.
`-3x + y = - 24`

Now, the equation is in standard form, with `A = -3, B = 1,` and `C = -24`.

 

Practice Problems 

Q`1`. If you have the equation `5x - 3y = 15`, what is the value of `A` in standard form? 

  1. `5` 
  2. `-3` 
  3. `15` 
  4.  `0`

Answer: a

 

Q`2`. Write the equation `y = 3 - 4x` in standard form.

  1. `y - 4x = 3` 
  2. `3 + 4y = x` 
  3. `4x + y = 3`
  4. None of the above

Answer: c

 

Q`3`. Write the polynomial `5x^2-9x^5+8x^3-11` in standard form.

  1. `-9x^5+8x^3+ 5x^2-11`
  2. `-8x^3+9x^5+ 5x^2-11`
  3. `-5x^2+8x^3+ 9x^5-11`
  4. `-11+5x^2+8x^3- 9x^5`

Answer: a

 

Q`4`. Write the polynomial `3x(2x+5 - 2x^2)` in standard form.

  1. `6x^2 +15x - 6x^3` 
  2. `- 6x^3  + 6x^2 +15x` 
  3.  `6x^3  + 6x^2 +15x `
  4.  `6x^2  + 5-2x^2  `

Answer: b

 

Frequently Asked Questions

Q`1`: Can any linear equation be represented in standard form? 

Answer: Yes, any linear equation can be represented in standard form. However, some equations may require more steps to convert due to fractional or decimal coefficients.

 

Q`2`: Can standard form be used for expressions with more than two variables? 

Answer: Yes, expressions with more than two variables can be written in standard form.

 

Q`3`. How do you convert an equation to standard form?

Answer: To convert an equation to standard form, rearrange the terms so that the variables `x` and `y` are on the left side of the equation, and all constants are on the right side. Ensure that the coefficient of `x` is non-negative, and the coefficients `A, B,` and `C` are integers. If necessary, multiply both sides of the equation by a common factor to eliminate any fractions.

 

Q`4`. Why is the standard form used for linear equations?

Answer: Standard form is used for linear equations because it provides a standardized and easily recognizable format for representing equations of lines. It allows for quick identification of the coefficients `A, B,` and `C`, which can be used to calculate the slope and y-intercept of the linear graph.

 

Q`5`. How is the standard form used in systems of linear equations?

Answer: Standard form is particularly useful when dealing with systems of linear equations, which involve multiple linear equations with the same variables. By expressing each equation in standard form, you can easily identify the coefficients and constants associated with each variable. This facilitates the process of solving the system of equations using methods such as substitution or elimination.