Find the prime factorization of each number?

Question

840

Answer 1

2³*3*5*7

This is very simple, you ought to be able to do it on a calculator. Just divide by numbers that go into it evenly... with 840, it is obvious that it divides by 2 and 5; once you remove those factors, you are left with 21, which you ought to recognise as 3*7. Just write down each factor as you divide by it, and once you are done, you will have your prime factorization.

Answer 2

Rule of thumb: if you add up all the digits and it is divisible by 3, then 3 is a prime factor. In this case, it's true.

840 = 3 x 280

Then you successively break down the big numbers. Note that 280 = 2 x 140

840 = 3 x 2 x 140

Now, break up 140

840 = 3 x 2 x 2 x 70

Now, break up 70

840 = 3 x 2 x 2 x 2 x 35

Now, break up 35. Note that 35 = 7 x 5

840 = 3 x 2 x 2 x 2 x 5 x 7

Now, put the prime factors into numerical order

840 = 2 x 2 x 2 x 3 x 5 x 7

That's it.

Answer 3

840=2^3*3*5*7

Answer 4

two to the seccond power times three times five

Answer 5

2
2
2
5
3
7