Question

Medal and Fan!

What is the LCD (Least Common Denominator) of 3/10 and -4/15?

Answer 1

What are your two different denominators here? List them, please.

Answer 2

I do not know, that's why I'm asking for help...

Answer 3

so..

Answer 4

You have two fractions. Every fraction has a denominator. I'm sure you can answer my question. Simply look at the 2 given fractions and identify the number on the bottom of each.

Answer 5

10 and 15, right?

Answer 6

yes.
Now factor 10 as far as possible. What are the factors?

Now factor 15 as far as poss. What are the factors of 15?

Answer 7

10 = 1, 2, 5,

Answer 8

right?

Answer 9

yes.

Answer 10

15=

Answer 11

Then the factor of 15 is 1,3,5

Answer 12

good.
so you have 10=2*5 and 15=3*5.

We see 5 as a factor of both.

Begin writing your L:CD now. start with 5.
What other factors of 10 and 15 do you see?

Answer 13

I don't understand, sorry.

Answer 14

The idea is to take all of the whole number factors of 10 and 15 and multiply them together.
Both 10 and 15 have 5 as a factor, so the LCD contains 5. 10 also contains 2, so take it; multiply 5 by 2; similarly 15 contains 3, take it and multiply your 5*2 by 3.

5*2*3=?

Answer 15

(5)(2)(3) = ?

Answer 16

@KylexChaos ?

Answer 17

I am trying to help you understand where LCDs come from. This is an essential skill. Do you want to continue, or not?

Answer 18

30!

Answer 19

@mathmale