# What is Fractions: Definition and 605 Discussions

A fraction (from Latin fractus, "broken") represents a part of a whole or, more generally, any number of equal parts. When spoken in everyday English, a fraction describes how many parts of a certain size there are, for example, one-half, eight-fifths, three-quarters. A common, vulgar, or simple fraction (examples:

1
2

{\displaystyle {\tfrac {1}{2}}}
and

17
3

{\displaystyle {\tfrac {17}{3}}}
) consists of a numerator displayed above a line (or before a slash like 1⁄2), and a non-zero denominator, displayed below (or after) that line. Numerators and denominators are also used in fractions that are not common, including compound fractions, complex fractions, and mixed numerals.
In positive common fractions, the numerator and denominator are natural numbers. The numerator represents a number of equal parts, and the denominator indicates how many of those parts make up a unit or a whole. The denominator cannot be zero, because zero parts can never make up a whole. For example, in the fraction 3/4, the numerator 3 indicates that the fraction represents 3 equal parts, and the denominator 4 indicates that 4 parts make up a whole. The picture to the right illustrates 3/4 of a cake.
A common fraction is a numeral which represents a rational number. That same number can also be represented as a decimal, a percent, or with a negative exponent. For example, 0.01, 1%, and 10−2 are all equal to the fraction 1/100. An integer can be thought of as having an implicit denominator of one (for example, 7 equals 7/1).
Other uses for fractions are to represent ratios and division. Thus the fraction 3/4 can also be used to represent the ratio 3:4 (the ratio of the part to the whole), and the division 3 ÷ 4 (three divided by four). The non-zero denominator rule, which applies when representing a division as a fraction, is an example of the rule that division by zero is undefined.
We can also write negative fractions, which represent the opposite of a positive fraction. For example, if 1/2 represents a half dollar profit, then −1/2 represents a half dollar loss. Because of the rules of division of signed numbers (which states in part that negative divided by positive is negative), −1/2, −1/2 and 1/−2 all represent the same fraction — negative one-half. And because a negative divided by a negative produces a positive, −1/−2 represents positive one-half.
In mathematics the set of all numbers that can be expressed in the form a/b, where a and b are integers and b is not zero, is called the set of rational numbers and is represented by the symbol Q, which stands for quotient. A number is a rational number precisely when it can be written in that form (i.e., as a common fraction). However, the word fraction can also be used to describe mathematical expressions that are not rational numbers. Examples of these usages include algebraic fractions (quotients of algebraic expressions), and expressions that contain irrational numbers, such as

2

2

{\textstyle {\frac {\sqrt {2}}{2}}}
(see square root of 2) and π/4 (see proof that π is irrational).

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1. ### Laplace transform of proper rational function

For this problem (b), The solution is, However, I don't understand how they got their partial fractions here (Going from step 1 to 2). My attempt to convert into partial fractions is: ##\frac{2s + 1}{(s - 1)(s - 1)} = \frac{A(s - 1) + B(s - 1)}{(s - 1)(s - 1)}## Thus, ##2s + 1 = A(s - 1) +...
2. ### Basic probability question (1 boy + 2 girls of a group of 7)

I know this problem can be done as follows. P(1 boy and two girls) = (C(2,1)*C(5,2))/C(7,3) = 20/35 My question can this be written as probility fractions? Meaning Lets say if that (2/5*3/7+1/2*1/7)/(3/7) But that doesn't give same result? what am I doing wrong?
3. ### LaTeX How to Represent Complex Fractions in LaTeX?

I know of two reasonable ways to represent a complex fraction: \dfrac{ \left ( \dfrac{a}{b} \right ) }{ \left ( \dfrac{c}{d} \right ) } ##\dfrac{ \left ( \dfrac{a}{b} \right ) }{ \left ( \dfrac{c}{d} \right ) }## and \dfrac{ ^a / _b }{ ^c / _d } ##\dfrac{ ^a / _b }{ ^c / _d }## What I am...

5. ### Solve for x and y in the given algebra problem involving fractions

*Kindly note that i created this question (owned by me). My Approach, ##\dfrac {(x+y)(4x+6y)}{(5x-5y)}##=##-1## ##(x+y)(4x+6y)=-5x+5y## ##\dfrac {4x+6y}{-5x+5y}##=##\dfrac {1}{x+y}## to get the simultaneous equation, ##4x+6y=1## ##-5x+5y=x+y## ... ##4x+6y=1## ##-6x+4y=0## giving us...
6. ### Definition of multiplying fractions -- help please

So the part in italics "an operation performed on one quantity which when performed on unity produces the other." I do not understand. Can anyone help me understand what this means? I know how to multiply fractions, but this explanation is confounding to me.

26. ### LaTeX Writing Fractions in LaTeX Easily

Hello all, So I've been trying to write some basic equations out like 1/2 but would like it to appear in a horizontal fashion (like 1 over 2). I have been reading threads on how to use latex, I've tried to look at others equations, right click and have the latex code shown to me so i can...
27. ### Simplifying algebraic fractions x in numerator and denom.

Homework Statement (x+3)(x-2)/x2-2x Homework EquationsThe Attempt at a Solution (x+3)(x-2)/x(x-2) = (x+3)/x What I don't understand is why I can't simplify this further for instance the x's cancel to give 1: (1+3)/1 = 4/1 = 4 Is it because there is no x next to the 3? Many thanks :)[/B]
28. ### Proof of an inequality with natural numbers

Homework Statement Prove that ##\forall n \in \mathbb{N}## $$\frac{n}{2} < 1 + \frac{1}{2} + \frac{1}{3} + \ldots + \frac{1}{2^n - 1} \leq n \text{ .}$$ Homework Equations Peano axioms and field axioms for real numbers. The Attempt at a Solution Okay so my first assumption was that this part...
29. ### MHB Inequality with fractions solve 2/(x^2−1)≤1/(x+1)

Dear all, I am trying to solve this inequality: $\frac{2}{x^{2}-1}\leq \frac{1}{x+1}$ I've tried several things, from multiplying both sides by $(x^{2}-1)^{2}$ finding the common denominator, but didn't get the correct answer, which is: $2<x<3$ or $x<-1$How to you solve this one ?
30. ### I How do Calculators add fractions with different denominators

How does computer technology add fractions with different denominators?

32. ### MHB Solve for J and B: Junhao & Bala Stamps Problem

Junhao and Bala both collect stamps. 1/3 of Junhao's stamps is equal to 3/5 of Bala's stamps. Junhao has 76 more stamps than Bala. How many stamps does each of them have? My answer: Number of stamps Junhao have =J Number of stamps Bala have = B We know that Junhao has 76 more stamps than Bala...
33. M

### Mathematica Decimals give different integrals than fractions; why?

Just like the title says. Is this due to roundoff?
34. ### Complex numbers: adding two fractions and solving for z

Homework Statement $$\frac{1}{z}+\frac{1}{2-z}=1$$ Homework Equations Quadratic-formula and algebra The Attempt at a Solution Been struggling with this one.. I keep getting the wrong answer, but that isn't the worst part, I can live with a wrong answer as long as the math behind it is...

Homework Statement For the solution to a given problem, in the second to last step I had: ##-\frac{\sqrt 6}{4} + \frac{\sqrt 2}{4}## I stated next that the solution was ##-\frac{\sqrt{6}+\sqrt{2}}{4}## I was told this was incorrect and that the correct solution is...
36. ### How to get the third value (A), using partial fractions

Homework Statement y(w)= 3/(iw-1)^2(-4+iw) Homework Equations N/A The Attempt at a Solution 3/(iw-1)^2(-4+iw) = A/iw-1 + B/(iw-1)^2 + C/-4+iw for B iw = 1 B=3/-4+1 = -1 for C iw = 4 C= 3/(4-1)^2 = 1/3 I know the answer for A should be -1/3 however I am unsure how to obtain this as if the...
37. ### I Partial Fractions: Explained

im a bit confused about partial fractions If we have something like x/((x+1)(x+2)) we could decompose it into a/(x+1) +b/(x+2) If we had something like x/(x+1)^2 we could decompose it into a/(x+1) + b/(x+1)^2 We use a different procedure when there is a square in part of the polynomial in...
38. ### MHB Is 2/3 Always the Same as 4/6?

Josh says that 2/3 is always the same as 4/6. Meghan says that 2/3 and 4/6 are equivalent fractions, but they could be different amounts. Which student is correct? I say Josh.
39. ### Mathematica How to Rearrange and Simplify Fractions in Mathematica for LaTeX?

Hello! I am new to Mathematica and I need some help with the code I attached. Can someone tell me how to pull the variables out of the fraction i.e. instead of ##\frac{7 p_1 p_2}{2 \cdot 5}## I would like ##\frac{7 }{2 \cdot 5} p_1 p_2## (I need this to make it look better for when I import it...
40. ### MHB Find the infinite sum of fractions 2/(3⋅5)+(2⋅4)/(3⋅5⋅7)+(2⋅4⋅6)/(3⋅5⋅7⋅9)+....

I´m not sure, whether this little challenge has been posted before. I have searched the forum and didn´t find it. It might still be a duplicate though ... Find the sum of fractions $$\frac{2}{3\cdot5}+\frac{2\cdot4}{3\cdot5\cdot7}+\frac{2\cdot4\cdot6}{3\cdot5\cdot7\cdot9}+...$$
41. ### MHB Which fractions can you make (with proof)?

Suppose you have the fraction 1/1. If you can make a fraction x/y, you can also make y/(2x). Also, if you can make x/y and a/b where GCD(x,y)=GCD(a,b)=1, you can make (x+a)/(y+b). Which fractions can you make?
42. ### MHB How to Simplify Fractions with Brackets

how do I work out this problem?19/20-(1/2-3/10)
43. D

### Simplifying Complex Fractions, final step

Homework Statement Please see attachment. Homework Equations I don't know how to get the final product on the ones with the question marks (textbook answers written next to them). I've gotten to the last step (except for # 29 but don't mind that one, I haven't exhausted all ideas). I've...
44. M

### I Optimizing fractions and Lagrange Multiplier

Hi PF! When minimizing some fraction ##f(x)/g(x)## can we use Lagrange multipliers and say we are trying to optimize ##f## subject to the constraint ##g=1##? Thanks
45. ### MHB 242 .10.09.8 Express the integrand as a sum of partial fractions and evaluate integral

$\tiny{242 .10.09.8}\\$ $\textsf{Express the integrand as a sum of partial fractions and evaluate integral}$ \begin{align*}\displaystyle I&=\int f \, dx = \int\frac{\sqrt{16+5x}}{x} \, dx \end{align*} \begin{align*}\displaystyle f&=\frac{\sqrt{16+5x}}{x}...
46. ### MHB Partial fractions ( part of a logistic equation)

Hi everyone, I am stuck on a problem. I need to give a partial fraction of 1/N(k-N). I have tried every method so far ( plotting roots, systems of equations). I think I found A=1/k but I have no clue how to find B value. I would really appreciate any help as I am a desperate student trying to...
47. ### MHB 206.07.05.88 partial fractions?

$\tiny{206.07.05.88}$ \begin{align*} \displaystyle I_{88}&=\int\frac{1}{(x+2)\sqrt{x^2+4x+3}} \, dx \\ &=? \end{align*} would partial fractions be best for this?
48. ### B Need materials to learn about different types of fractions

Trouble here in the below partial fraction (Bug) $\frac{5x^2+1}{(3x+2)(x^2+3)}$ One factor in the denominator is a quadratic expression Split this into two parts A&B $\frac{5x^2+1}{(3x+2)(x^2+3)}=\frac{A}{(3x+2)}+\frac{Bx+c}{(x^2+3)}$...
In my physics courses I have seen this kind of notation several times now: $$\frac {A/B} {C}$$ For instance: or To me it doesn't seem intuitive and ## \frac A {BC}## would seem like a neater way of writing it. Therefore I wonder if there's any specific reason to why people write it...