147abc = 3 x 7 x 7 x a x b x c

Basically, you use prime factorization x variables.

52

0.506, 0.56, 0.605, 0.65

Non-examples are infinite. One relevant one is a number that cannot be divided into a number.

Since 18 is a factor of 90 and it is the largest factor of itself, the greatest common factor of 18 and 90 is 18.
Since 18 is a factor of 90, it is automatically the GCF.

1 x 310, 2 x 155, 5 x 62, 10 x 31.

The GCF is 3.

288

1 x 330, 2 x 165, 3 x 110, 5 x 66, 6 x 55, 10 x 33, 11 x 30, 15 x 22

The answer is 10 20 and 30.

It is not possible to give a sensible answer to this question. The least common multiple (LCM) refers to a multiple that is COMMON to two or more numbers. You have only one number in the question!

20

What is the gcf of 21,35,14 and 28?

The GCF is 14.

To find a missing factor you need an equation. Is this supposed to be 4f = 11?

Then the answer is f = 11/4 or 2 3/4 or 2.75

To find the HCF of two numbers you first need to express them as the product of their prime factors. In this case you'd get:

45 = 3x3x5

60 = 2x2x3x5

The next step is to identify any common prime factors. In this case both numbers have a 3 and a 5 as a prime factor. Multiplying these together gives:

3x5 = 15

And so 15 is the HCF of 45 and 60.

4 8 12 16

List the multiple of 11between 56 and 122

Any even exponent of 8.

126

Step 1: Multiply them together.

Step 2: Write it down.

There are infinitely many such pairs of numbers. As long as the only primes they have in common are 2×3²×5 (the prime factorization of 90) their gcf will be 90:

Some examples:

90, 180

90, 270

90, 360

180, 270

180, 450

450, 630

630, 990