I don't have any specific problems I need help with, but I'm a bit confused about two things:

1) Where 2^x - 1 = y, is x or y the Mersenne prime?

2) I have noticed that in some cases, such as 27 * 3, I can break the problem up and arrive at the correct result:

27 * 3 = 81

(20 * 3) + (7 * 3) = 60 + 21 = 81

Does this work in all cases? I'm having trouble finding a problem that isn't correctly solved this way, but in the past I have tried this and arrived at the wrong answer. Does anyone know how this works?

2) it works in all cases.

(a+b)c=a*c + b*c is why this is true.

1) y is the Mersenne Prime. And, big news in that area, the first 44 are now known.

http://www.mersenne.org/

I see, thanks. I must have been doing it wrong when it didn't work.

Let's address your questions one by one:

1) In the equation 2^x - 1 = y, the variable x represents the exponent, and y represents the resulting value. This equation is related to Mersenne primes. A Mersenne prime is a prime number of the form (2^x) - 1.

To determine if the equation represents a Mersenne prime, you need to find a number for x that makes the expression 2^x - 1 equal to a prime number. In other words, if y is a prime number, then the equation represents a Mersenne prime where x is the exponent.

For example, let's consider the equation 2^4 - 1 = 15. In this case, y is not a prime number, so it does not represent a Mersenne prime.

On the other hand, if we take the equation 2^7 - 1 = 127, we find that y is a prime number. Therefore, in this case, x represents the exponent of the Mersenne prime.

2) Breaking down multiplication into smaller parts can be done using the distributive property of multiplication over addition. This property states that a * (b + c) = a * b + a * c.

In your example, 27 * 3 = (20 * 3) + (7 * 3). You broke down 27 into 20 and 7 and calculated the product with 3 separately. By applying the distributive property, you correctly obtained the result of 81.

This method does work for all cases of multiplying two numbers. You can break down each number into smaller parts and calculate the products individually, then sum them up to obtain the final result. This process is known as the "distributive property" or "partial product method" in arithmetic.

However, it is important to note that this method might not be the most efficient approach for larger numbers. In such cases, alternative algorithms like column multiplication or long multiplication are more commonly used.

It is possible that in the past, when you tried breaking down a problem and arrived at the wrong answer, there might have been a mistake in your calculations or an error in applying the distributive property. Double-checking your calculations and understanding the method should help you achieve accurate results.