Answered

Sumali sa IDNStudy.com at simulang makuha ang maaasahang mga sagot. Sumali sa aming platform upang makatanggap ng mabilis at eksaktong tugon mula sa mga propesyonal sa iba't ibang larangan.

Hello,

I need to factor out

x^2 - 7x +12 = 0

and this is what I did...
I factored out the -7x
⇒ x^2 - 4x - 3x +12 = 0
Then I grouped them

⇒ (x^2 - 4x) - (3x +12) = 0
⇒ x (x - 4) - (????) = 0

That's where I'm lost
 I can't seem to be able to factor out -(3x+12) into having a factor of (x-4)
it always comes out as -3(x+4)

I hope someone can help. :)

Sagot :

AnneCidn
It should be -3(x-4) because the negative sign will also be distributed so it will be equal to -3x+12 which is what is in the original equation.

You made a mistake in grouping the terms here: (x² - 4x) - (3x +12) = 0

You should've included the negative sign for 3x: 
(x² - 4x) + (-3x +12) = 0
or changed +12 to -12 since you initially factored out the - sign: 
(x² - 4x) - (3x -12) = 0

Any of these two would've given you the right answer :)

If you used -3(x+4), that will be equal to -3x -12, which is not similar to the equation.


Btw, i like how you factor :) It's different from how a typical high school student does it
Roshelleidn
Answer: (X - 3)(X - 4)