hi totally went blank i need to know what 81's prime numbers are! i really appreciate it!
2006-10-19 12:46:41 · 9 answers · asked by Rachel S 1 in Science & Mathematics ➔ Mathematics
3^4
2006-10-19 12:48:18 · answer #1 · answered by MsMath 7 · 0⤊ 0⤋
What is Prime Factorization mean?
Always start with a definition of math terms BEFORE solving the questions.
Prime Factorization
By expressing numbers as products of prime factors, it is easy to find their Greatest Common Divisor, or their Least Common Multiple.
First, you should know what a prime number is. It's a number that can't be written as the product (that means by multiplying together) smaller numbers. An example is 5. Number 5 can't be written as the product of any smaller numbers. Its only factors are 1 and 5.
The Sieve of Eratosthanes can be used to find prime numbers. Using this method, we see that the first few prime numbers are 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, and 97.
A good way to find the prime factorization of a number is to see if it can be divided by these small primes. If it can, then "take out" those factors, and try dividing the quotient by small primes. Each of these successful divisions will give you one prime factor. When you're left with a prime number at the end, then you're done.
Sample:
Find the prime factorization of 24:
24 ÷ 2
12 ÷ 2
6 ÷ 2
3
Now the last number written on each line is a prime number, so the method is not only easier to write, but it is clearer to see, as well. Again, the prime factorization of 24 is 2 × 2 × 2 × 3. This can be written as 2^3 × 3. The little "3" is called an exponent, and means that the 2 appears three times as a factor of 24. You say this "two to the power three times three".
Now let's use the method with a different number.
Back to your question.
The Prime Factorization of 81 = 3 to the fourth power, which is
3 x 3 x 3 x 3 written 3^4.
Guido
2006-10-19 13:11:10 · answer #2 · answered by Anonymous · 0⤊ 0⤋
Prime Factorization Of 81
2016-09-28 08:40:40 · answer #3 · answered by ? 4 · 0⤊ 0⤋
3 x 3 x 3 x 3 = 81
Obviously 2 doesn't work, so start with 3.
81 / 3 = 27
27 / 3 = 9
9 / 3 = 3
3 / 3 = 1
So the prime factorization is 3 x 3 x 3 x 3, which is also 3^4 (3 to the fourth power).
2006-10-19 12:51:09 · answer #4 · answered by Puzzling 7 · 0⤊ 0⤋
Prime factorization of 81:
3x3x3x3; 3^4 (three to the power of four)
2006-10-20 02:09:41 · answer #5 · answered by ludacrusher 4 · 0⤊ 0⤋
the prime factorization of 81 is 3 to the fourth power!
2006-10-19 13:31:30 · answer #6 · answered by scott s 1 · 0⤊ 0⤋
It only has 3 and 1 ( is 1 a prime? I can never remember ).
2006-10-19 12:53:12 · answer #7 · answered by Anonymous · 0⤊ 0⤋
3, 9
2006-10-19 12:48:50 · answer #8 · answered by CHEEKY 3 · 0⤊ 0⤋
3 to the fourth power
2006-10-19 13:02:48 · answer #9 · answered by Anonymous · 0⤊ 0⤋
9x9
3x3x3x3
2006-10-19 12:48:18 · answer #10 · answered by Anonymous · 0⤊ 0⤋