Products of prime numbers?

Question

Help!
Missed college and just been told I need to write these numbers as a 'product of prime numbers' today.
28,30,45,50,51,52,54,60,
63,64,70,72.
Wha are they talking about?

Answer 1

Welcome to the class.
Summarizing the previous teachers:
The prime numbers to 20 are:
2, 3, 5, 7, 11, 13, 17, 19. (Memorize this.)

Always begin with the lower numbers,

28 = 28 / 2 = 14; 14 / 2 = 7. so 28=2x2x7
30 = 30 /2 =15; 15 / 3 =5. so 30= 2x3x5
45 = 45 / 3 =15; 15 /5 =5 so 45 = 3x3x5.

Do the others for home work.
All the best.

Answer 2

Dude, they want you to split these numbers into prime numbers according to the products.
i e .,
28=14*2=7*2*2
which means all the numbers 7,2,2 must be prime.

Generally, Y=X*Z
then, Y and Z both must be prime.

Similarly,
30 = 6*5 = 2*3*5
45 = 9*5 = 3*3*5
50 = 10*5 = 2*5*5
51 = 17*3
52 = 13*2*2
54 = 2*3*3*3
60 = 2*2*3*5
63 = 3*3*7
64 = 2*2*2*2*2*2
70 = 2*5*7
72 = 2*2*2*3*3

Hope thats the thing.
Peace out.

Answer 3

College??? Prime Numbers???? What did they teach you in Junior School?? You shouldn't be in College.

Prime number are numbers that divide by only themselves and 1. If you do not know that then I can assume only 2 things, the teachers in the UK are worse than down here or you weren't paying attention in class. If it's the first, Blair should quit right now, if it's the second then you better wake up. The first 3 primes no.s except 1 are 2,3 and 5. The rest put your head to work.

Answer 4

To do all these you just need to divide in the prime numbers one by one until you get down to one. Start with 2 and then use 3,5,7,11 etc

For example 28
28= 2 x 14
= 2 x 2 x 7

Another example 60
60 = 2 x 30
= 2 x 2 x 15
= 2 x 2 x 3 x 5 and so on.

You need to do the rest yourself if you are to understand!

Answer 5

Write down a succession of prime numbers. Then by multiplying and numbers(product) until you reach the appropriate answer.
eg Prime numberA x prime number B= 28
you may need to use more than two numbers for your
product.

Answer 6

a prime number is only divisible by itself and unity

therefore,

28=2^(2)x7
30=2x3x5
45=3^(2)x5
50=2x5^(2)
51=3x17
52=2^(2)x13
54=2x3^(3)
60=2^(2)x3x5
63=3^(2)x7
64=2^(6)
70=2x5x7
72=2^(3)x3^(2)

the above are all products of prime numbers

Answer 7

400-Digit Product of Two Primes [11/04/2002]: What two prime numbers when multiplied together will equal a 400-digit number? ...

Answer 8

28=2* 2* 7
30=2*3*5
45=3*3*5
50=2*5*5
51=3*17
52=2*2*13
54=2*3*3*3
60=2*2*3*5
63=3*3*7
64=2*2*2*2*2*2
70=2*5*7
72=2*2*2*3*3
try to learn how to find factors of a number.
but first try to learn divisibility rules by 2,3,4,5,6,7,8,9,10,11

Answer 9

sorry about this comment but that topic is actually taught in elementary but anyways,,...
28=2* 2* 7
30=2*3*5
45=3*3*5
50=2*5*5
51=3*17
52=2*2*13
54=2*3*3*3
60=2*2*3*5
63=3*3*7
64=2*2*2*2*2*2
70=2*5*7
72=2*2*2*3*3

Answer 10

They are talking about factorization, read about it here: http://en.wikipedia.org/wiki/Integer_factorization

For such small numbers, the best method is "trial division" (look it up as well) where you try to divide your number by descending prime numbers. (Look up prime numbers here http://en.wikipedia.org/wiki/Prime_numbers if you don't know about primes).
For example 28 = 2 * 2 * 7