Write the answer to this calculation as the product of powers of prime numbers..

123 Views Asked by At

Write the answer to this calculation as the product of powers of prime numbers:

$$4^3\times9^3\times20^2$$

I've browsed a few related questions suggested and I don't think the ones I have found are as basic as what I'm asking. I'm doing an online maths course to get back my long forgotten A-Level maths and I have came across this question;

I am happy to work out the value of the given calculation and then factorise by table until I find the answer, I'm comfortable with getting the right answer doing it that way. My question was more, is there a more elegant way, that the course is expecting, that I am missing?

I've stared at it for a while trying to see through any obvious relationships in the numbers and came up with nothing though my maths brain has been dormant for a decade. I'm not looking for a solution, but more a suggestion that 'yes, there is a cleaner way than just working out the big number and factorising down'. If there ISN'T then great, I know what to do :)

I'm sure there are various equations that tackle this, though bear in mind I am taking a first year A-Level course so I'm more curious that I am missing something fundamental..

Thanks for your time on this unbelievably easy question for most of you guys!

1

There are 1 best solutions below

0
On BEST ANSWER

We will use the rules $a^k \times a^j = a^{k + j}$ and $(a^k)^j=a^{kj}$ repeatedly to simplify. The first step is to break each term into primes then simplify and rearrange them to get it into the final form. The calcluation goes as follows: $$4^3 \times 9^3 \times 20^2=(2^2)^3 \times (3^2)^3 \times (2^2 \times 5)^2=2^6 \times 3^6 \times 2^4 \times 5^2 = 2^{6 + 4}\times 3^6 \times 5^2=2^{10}\times 3^6 \times 5^2$$