Factor Using Distributive Property (Check) MEDAL REWARDED!!
1)x^2-7x+12 =(x-3)(x-4) right?
2)x^2-16 =(x+4)(x-4) right?
3)x^2-12x+36 =(x-6)(x-6) right?
So it is (x-3)(x-4) right?
How did you get that?
Here's how you check: \[(x-3)(x-4) = x*x -4*x - 3*x + 12 = x^2 - 7x + 12\checkmark\]
So it's correct? @whpalmer4
That's what that big checkmark means, yes. Multiply them out carefully and compare with what you started with. If they are equal, your answer should be correct.
Oh yea, forgot to read that, thanks a lot @whpalmer4 You deserve a medal! :D
Do you mind if you check the rest?
I have to go to a workshop later in a like a hour later.
Really, you should check them yourself by multiplying them. That's how you get to be good at doing the algebra — practice! Also, it helps you recognize later when factoring how you got the results when multiplying.
Okay
but yes, all 3 are correct. good work!
multiply them, for me :-)
Can you just help me with the second one, for another example so then I will know how to do it better?
and for you!
Thanks!
\[(x-4)(x+4) = x^x +4x -4x -16 = x^2 -16\] I don't actually multiply this when I see it, but rather recognize it as a difference of squares: \[(a+b)(a-b) = a^2-b^2\]Learn to recognize that in both directions and you'll save yourself some work over the years :-)
Can you help me find the answer to this one? I am stuck on this problem. Here it is: 24^2b^2-18ab
\[24^2b^2-18ab\]is that it?
Thanks @whpalmer4 for showing the steps! :D
Yes
there's only one \(a\) in there?
Wait 24a^b^2 etc..
write it out exactly, please...
Okay
24a^2b^2-18ab
one of the most valuable things learned in math class, in my opinion, is attention to detail and careful work :-)
Indeed
\[24a^2b^2-18ab\]and we want to factor this? Do you see any common factors?
Would it be 6?
we can factor out a 6, yes. what would we have after doing that?
Do something with a (a & b)?
no, please write out the expression after factoring out a 6...
\[6(...\]
Is it correct? (answer) 6(ab)
Let me restate that. What do you get if you divide \(24a^2b^2-18ab\) by \(6\)?
Wait for a minute or so...
all you are doing is dividing the numbers in front of \(a^2b^2\) and \ab\) by 6. 24/6=? 18/6=?
6(ab) I am not sure, I am confused..
No, where do you get this \(6(ab)\) stuff from? Do you really not know how to divide \[\frac{24a^2b^2}{6}\] ?
what is \[6*4a^2b^2\]?
We just learned this unit today, so you know...
24a^2 b^2?
you just learned how to multiply variables and numbers together today, and you're factoring trinomials? if you say so... Yes, \[6*4a^2b^2 = 24a^2b^2\]So\[\frac{24a^2b^2}{6} = \frac{24}{6}a^2b^2 = 4a^2b^2\] What does \[\frac{18ab}{6}=\]
3ab?
yes! So, if we factor out a 6 from our expression, we have: \[6(4a^2b^2 - 3ab)\] Agreed? Do you see any other factors which appear in both terms of the expression in the parentheses?
Yes I agree thank you! You are my lifesaver!! :D
Yes a&b
4-3 too?
Good, \(a\) and \(b\) are both common factors. Not so good on the \(4-3\), though — does it appear in BOTH terms?
Oh okay..
So do we subtract the a and b exponents?
Remember, the stuff in the parentheses could be written like this: \[2*2*a*a*b*b-3*a*b\] If we line them up over each other: 2*2* a*a*b*b 3*a* b The only thing both rows have in common is \(a\) and \(b\), and only one of each, right?
(scanning down the columns)
Yes
so we can factor \(ab\) out of each term. What is \[\frac{4a^2b^2}{ab}=\]? What is \[\frac{3ab}{ab}=\]?
4ab?
3
One's for the first and second answer
good. and good. so, if we factor \(ab\) out of \(24a^2b^2-18ab\), how do we write the result?
6(4ab+3)?
uh, no, not quite. \[24a^2b^2-18ab = 6(4a^2b^2-3ab) = 6ab(4ab-3)\]
Oh okay, thanks :D
Can you help me with this one too, I am not going with variables @whpalmer4
a+a^2b+a^3b^3
\[a+a^2b+a^3b^3\]Do you see any common factors?
No, I think
No? Seriously? Doesn't \(a\) appear in each term?
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