This discussion board is a place to discuss our Daily Challenges and the math and science
related to those challenges. Explanations are more than just a solution — they should
explain the steps and thinking strategies that you used to obtain the solution. Comments
should further the discussion of math and science.
When posting on Brilliant:
Use the emojis to react to an explanation, whether you're congratulating a job well done , or just really confused .
Ask specific questions about the challenge or the steps in somebody's explanation. Well-posed questions can add a lot to the discussion, but posting "I don't understand!" doesn't help anyone.
Try to contribute something new to the discussion, whether it is an extension, generalization or other idea related to the challenge.
Stay on topic — we're all here to learn more about math and science, not to hear about your favorite get-rich-quick scheme or current world events.
Markdown
Appears as
*italics* or _italics_
italics
**bold** or __bold__
bold
- bulleted - list
bulleted
list
1. numbered 2. list
numbered
list
Note: you must add a full line of space before and after lists for them to show up correctly
What you have to do is start by finding the coefficients on p. Since it's a 3, you know it will look like
(3p q)(p q) where you have to fill in the rest of the numbers. Now, you have to guess and check where to put the 2, and it will have a - either in front of it or in the other factor. You have to fumble around this one, and you will get (3p-q)(p-2q).
Another method, a bit more complicated, works if you don't want to guess and check, like if you have a number with a lot of factors like 12 or 24. Treat the q's as constants, and look at the expression as a quadratic in p. Basically, 3p^2+(5q)p+(-2q^2). You then apply the quadratic formula with a=3, b=5q, and c=-2q^2. Doing this, you get (-5q p/m 7q)/6, which gets you -2q and q/3 depending on the p/m. These, if you remember, are the roots of the equation. To factor, you take the variable (p here) and subtract from that the roots you found, and multiply the two expressions. (p- (-2q))(p-q/3)=(p+2q)(p-q/3) (just like how you would normally do it). Now, you just have to multiply by a number to make sure the coefficients match up. Multiply by 3: 3(p+2q)(p-q/3)=(p+2q)(3p-q) (we could put it on the other factor, but then we'd still have that fraction).
To answer the general question, you may not always be able to factorize an algebraic expression (apart from the trivial factorization). See for example Factorization - Test Yourself 3.
it is simple you treat p only as variable. in the quadratic equation ax'2+bx+c, rewrite b so as the product of two integers is equal to aXc and their sum or difference should be equal to b , sum or difference is depends up on the signs of the a and c. after that bringing out the necessary common terms, we can write them product of two factors.
32=6, 61=6, 6-1=5,
3p'2+6pq-pq-2q*2=3p(p+2q)-q(p+2q) = (p+2q)(3p-q)
this method has some limitations that when there exists integer factors only.
Easy Math Editor
This discussion board is a place to discuss our Daily Challenges and the math and science related to those challenges. Explanations are more than just a solution — they should explain the steps and thinking strategies that you used to obtain the solution. Comments should further the discussion of math and science.
When posting on Brilliant:
*italics*
or_italics_
**bold**
or__bold__
paragraph 1
paragraph 2
[example link](https://brilliant.org)
> This is a quote
\(
...\)
or\[
...\]
to ensure proper formatting.2 \times 3
2^{34}
a_{i-1}
\frac{2}{3}
\sqrt{2}
\sum_{i=1}^3
\sin \theta
\boxed{123}
Comments
(3p - q)(p +2q)
Log in to reply
thanxxxx...
3p^2 + 6pq - pq - 2q^2 3p(p+2q) -q(p+2q) (p+2q)(3p-q)..... ........... in this way it can be solved
What you have to do is start by finding the coefficients on p. Since it's a 3, you know it will look like (3p q)(p q) where you have to fill in the rest of the numbers. Now, you have to guess and check where to put the 2, and it will have a - either in front of it or in the other factor. You have to fumble around this one, and you will get (3p-q)(p-2q).
Another method, a bit more complicated, works if you don't want to guess and check, like if you have a number with a lot of factors like 12 or 24. Treat the q's as constants, and look at the expression as a quadratic in p. Basically, 3p^2+(5q)p+(-2q^2). You then apply the quadratic formula with a=3, b=5q, and c=-2q^2. Doing this, you get (-5q p/m 7q)/6, which gets you -2q and q/3 depending on the p/m. These, if you remember, are the roots of the equation. To factor, you take the variable (p here) and subtract from that the roots you found, and multiply the two expressions. (p- (-2q))(p-q/3)=(p+2q)(p-q/3) (just like how you would normally do it). Now, you just have to multiply by a number to make sure the coefficients match up. Multiply by 3: 3(p+2q)(p-q/3)=(p+2q)(3p-q) (we could put it on the other factor, but then we'd still have that fraction).
Log in to reply
thanx..
its simply a quadratic equation involving two variables
To answer the general question, you may not always be able to factorize an algebraic expression (apart from the trivial factorization). See for example Factorization - Test Yourself 3.
it is simple you treat p only as variable. in the quadratic equation ax'2+bx+c, rewrite b so as the product of two integers is equal to aXc and their sum or difference should be equal to b , sum or difference is depends up on the signs of the a and c. after that bringing out the necessary common terms, we can write them product of two factors. 32=6, 61=6, 6-1=5, 3p'2+6pq-pq-2q*2=3p(p+2q)-q(p+2q) = (p+2q)(3p-q)
this method has some limitations that when there exists integer factors only.
Log in to reply
32=6, 61=6, 6--1=5
You can divide the whole equation by \p or \q assuming they are not equal to 0, then the question becomes a problem of solving a quadratic equation.
3p2 + 5pq-2q2
=> 3p2 + 6pq-pq - 2q2
=> 3p(p+2q) -q(p+2q)
=> (3p-q)(p+2q) = ans