I'll choose the brainliest answer plus 25 points [18 points for the answer and 18 plus 7 points for the brainliest answer] for those who will answer me so please help me.

I'm really having trouble catching up about adding and subtracting rational expressions with dissimilar denominator since I'm always pulled-out in Math class because I always have rehearsals in Glee Club.
P.S. I need this until "2015.09.20". But please answer as soon as possible and don't enter absurd answers just to get points or just because you wanted to. Thank you so much.

So here are my questions:

1.) How to find the LCD when the other denominator doesn't have a variable or constant like 6x and 3? [3 doesn't have a variable]
2.) How to find the LCD of a binomial? [e.g. 5x - 20 and x - 4]
3.) What are the other things I should know about adding and subtracting rational expressions whether it has similar or dissimilar denominator?

Are you saying LCM?
LCD - Least Common Denominator or LCM - Least Common Multiple
So yeah. It's either LCM or LCD.


The Brainliest Answer!

This Is a Certified Answer

Certified answers contain reliable, trustworthy information vouched for by a hand-picked team of experts. Brainly has millions of high quality answers, all of them carefully moderated by our most trusted community members, but certified answers are the finest of the finest.
1) In order for you to know the LCM of a monomial (a number with a variable) and a constant you can just simply get the factors.

When you are asked to get the LCM of let’s say 12 and 24, we would quickly know that it is 24. But what should you do to get the LCM of for example, 6x and 3?

We first get the factors of each term
6x = 2 * 3 * x
3 = 3

So the LCM would be combining all the factors, getting the highest exponent of the bases seen, so the LCM is 2 * 3 * x = 6x.

2) We need to get the factors of each binomial, we get the GCF of the terms in each binomial. To get the GCF it is similar to getting the LCM except that you get the common factors.

In order to get the LCM of the binomial we factor each.

First, factor 5x -20
5x = 5 * x
20 = 5 * 2²

GCF = 5

5x - 20 = 5(x - 4)
x - 4 = x - 4

LCM = 5 * (x - 4) = 5x - 20

3) You need to have the same denominator before adding the numerators. Simplify each fraction if possible.
2 5 2