Is There a Faster Way to Factor Than Just Guessing Factors?

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In summary, the conversation revolved around a quadratic formula problem that required factoring numbers to find their product and sum. However, the given numbers did not have any real solutions. The suggested method was to use small prime numbers to check for factors and solve the equation.
  • #1
Tyrion101
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One of my quadratic formula problems required me to factor so that the product of 2050s factors added to -23, that may not be exact, but I basically asked for a new problem since it was just practice, after an hour of getting close but never the right answer, and I was wondering, other than just using the computer program I wrote (which would likely be cheating) is there anything that gets me an answer faster than just guessing factors?
 
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  • #2
So you were supposed to find numbers a,b such that their product is 2050 and their sum is -23? That is not possible (at least not with real numbers).

Anyway, I would do it like that:
As a+b=-23, we can write b=-23-a.
Plug this into a*b=2050 and you get a regular quadratic equation. With the numbers in your post, it does not have solutions, but with other numbers it has.
 
  • #3
You had something like x^2 - 23x + 2050?

2050
2 - 1025
5 - 205
5 - 41
41 - 0

2050 is 2.5^2.41

Knowing the small primes helps. For example, I knew that 41 is prime. But also, there is an easy way to check. If a number n is composite, it has a prime factor ≤ ##\sqrt{n}##. So with 41, if it is composite, it has a prime factor < 7, so check 2,3,5, none divides it, so it is prime.
 

1. What is factoring?

Factoring is the process of finding the factors of a given number or expression. Factors are numbers or expressions that can be multiplied to get the original number or expression.

2. Why is factoring important?

Factoring is important because it allows us to simplify complex expressions and solve equations. It is also useful in real-world applications such as finding the dimensions of a rectangle with a given area.

3. What is the traditional method of factoring?

The traditional method of factoring involves grouping terms, looking for common factors, and using algebraic techniques such as FOIL or the quadratic formula. It can be time-consuming and requires a good understanding of algebra.

4. What is an easier way of factoring?

One easier way of factoring is using the "guess and check" method, where you try to find factors by testing different numbers until you find the right one. Another easier way is using the "difference of squares" method for special cases.

5. Can factoring be done for all numbers or expressions?

No, factoring can only be done for numbers or expressions that can be written as a product of two or more factors. Some numbers or expressions, such as prime numbers, cannot be factored any further.

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