Step-by-step solution on how to factor (x-y-2z)^2-(2x+y-z)^2
use the identiy : \(a^2-b^2 = (a+b)(a-b)\)
@ganeshie8 yes, but would you mind showing the full solution?
give it a try, i can have a look once u r done :)
@ganeshie8 tried it already, but i seem to be getting the signs all mixed up. here's what i keep getting:\[=(x-y-2z+2x+y-z)(x-y-2z-2x-y+z)\]\[=(3x-3z)(-x-2y-z)\]\[=3(x-z)(-x-2y-z)\] but the correct answer is actually 3(z-x)(x+2y+z)
Excellent ! your answer is also correct
=3(x-z)(-x-2y-z) =-3(x-z)(x+2y+z)
=3(x-z)(-x-2y-z) =-3(x-z)(x+2y+z) = 3(z-x)(x+2y+z)
@ganeshie8 but i was not able to come up with a negative answer... i checked my answer again and i did not bring out a negative sign even if my answer is just the negative of the correct answer.
u got the below answer :- 3(x-z)(-x-2y-z) right ?
take -1 common in last factor and see wat u get
@ganeshie8 yes, but i don't understand where the -1 is coming from...?
3(x-z)(-x-2y-z) ^ ^ ^
(-a-b-c) can be written as -(a+b+c)
this much should be easy to see ha ?
@ganeshie8 i got the answer 3(x-z)(-x-2y-z) whereas the correct is 3(z-x)(x+2y+z) but wouldn't my answer only be correct if there were a negative sign before it? because my answer is the negative of the correct answer but clearly, there is no negative sign before my answer, making both answers positive; thus, totally different. am i missing something?
yes u r overlooking another thing
in ur answer, u have (x-z)
where as the so called correct answer, u have (z-x)
getting ? :)
so both are same
(x-z) = -(z-x)
@ganeshie8 i understand clearly that (x-z)=-(z-x) but the thing is both answers are POSITIVE as in, (x-z) and (z-x), there is NO NEGATIVE SIGN... so....? is my question confusing you?
whats ur question ?
@ganeshie8 that my answer (x-z) is DIFFERENT from the correct one which is (z-x). so how do i get to the correct answer (z-x) from my answer (x-z) if my answer is not the negative of the correct answer? would you mind showing your solution to make everything clearer? i i find it a bit hard to understand without showing the actual figures.
i gave u the solution already above, maybe, just lay back and look at it again you will see. good luck !
my 4th reply has the solution
\begin{align} \large 3(x-z)(-x-2y-z) &=\large 3(x-z)\cdot \color{red}{-1}(x+2y+z) \\ &=\large \color{red}-3(x-z)(x+2y+z) \\ &=\large -3(x-z)(x+2y+z) \\ \end{align}
In reference to what @ganeshie8 was talking about.
Join our real-time social learning platform and learn together with your friends!