How do you find the LCD of 5 6 and 7?

Answer 1

The same as with two.
Example: 30, 42, 60
Factor them.
2 x 3 x 5 = 30
2 x 3 x 7 = 42
2 x 2 x 3 x 5 = 60
Combine the factors, eliminating duplicates.
2 x 2 x 3 x 5 x 7 = 420, the LCD

Answer 2

Say there's 2/3 and 1/2, it's called Least Common Denominator, so you need to look at the denominators which are 3 and 2.

Now list the multiples:

3: 1, 3, 6...

2: 1, 2, 4, 6...

As you can see both of them go into 6 the least amount of times because it's the one that they both can multiply.

Answer 3

Example: 1/30 and 1/42
Factor them.
2 x 3 x 5 = 30
2 x 3 x 7 = 42
Combine the factors, eliminating duplicates.
2 x 3 x 5 x 7 = 210, the LCD

Answer 4

By multiplication: 5*6*7 = 210