Showing posts with label Adding Fractions. Show all posts
Showing posts with label Adding Fractions. Show all posts

Monday, October 29, 2012

Adding Fractions with Negative Numbers

Introduction for Adding Fractions with Negative numbers:

A fraction (from the Latin fractus, broken) is a number that can represent part of a whole. The earliest fractions were reciprocals of integers: ancient symbols representing one part of two, one part of three, one part of four, and so on. A much later development were the common or "vulgar" fractions which are still used today (½, ?, ¾, etc.) and which consist of a numerator and a denominator.

Source – Wikipedia.

Adding Fractions with Negative Numbers – Method 1:
The examples show the adding the fractions with negative numbers.

This is the formula to calculate the algebraic fractions for addition is ` a/b + c/d` = `(ad + bc) / (bd)` .

Adding the fractions: `-3/5 + 2/8 `

Solution:

Multiply the numerator and denominator

= `(-3xx8 + 2xx5) / (5xx8)`

Then adding the numerator

= `(-24 + 10) / 40`

= `-14/40` .
By reducing this fraction we get `-7/20` .

Adding the fractions: `4/6 + (-3)/7`

Solution:

Multiply the numerator and denominator

= `(4xx7 + 6xx-3)/(6xx7)`

Then adding the numerator

= `(28 - 18)/42`

= `10/42`

By reducing this fraction we get `5/21` .

Adding the fractions: `15/-6 + 10/-2`

Solution:

Multiply the numerator and denominator

= `(15xx-2 + (-6)xx10)/(-6xx-2)`

Then adding the numerator

= ` (-30 - 60)/-12`

= `-90/-12`

By reducing this fraction we get `15/2` .

I am planning to write more post on rational numbers definition, rounding to the nearest tenth. Keep checking my blog.

Adding Fractions with Negative Numbers – Method 2:
The examples show the adding the fractions with negative numbers.

Adding the algebra fractions: `-3/4 + 9/-7` .

Solution:

LCM for the denominators in the fractions are

The LCM of 4, -7 = -28

So `(-3xx-7)/(4xx-7)` = `-21/-28`

`(9xx4)/(-7xx4)` = `36/-28`

Denominators are equal and adding the numerator in the fractions.

= `-21/-28+36/-28`

= `(-21+36)/-28`

= `15/-28` is the solution.

Adding the algebra fractions: `(-8x)/11 + (-10x)/4` .

Solution:

The given fractions are

= `(-8x)/11 + (-10x)/4`

LCD for the denominators 11 and 4 is 44.

= `(-8xxx4)/44+((-10x)xx11)/44`

To express the denominators in the LCD form as

= `(-32x)/44+(-110x)/44`

We can simplify the numerators.

=` (-32x-110x)/44`

We can add the numerators.

= `(-142x)/44`