what about this one?
No, both are wrong (first one in the answer, second one in the writing)
In the first one, you must write both answers :
The second one has the correct answer but is not correctly written. Here is an example of how it should be written :
EDIT : talking about the first question in this post ...
The other question you posted is wrong too
I am not taking account of the quadratic equation written on it because I do not see the link with the following.
Here is how you do it :
--> This is where you messed up : you did not factorize the .
Or, more conveniently :
Remember that . Here, you have :
This can be written :
The common factor is two, so you factorize it over the addition. Since you are factorizing all the (and not !), they become (some people prefer to remove them directly though) :
Now you can cancel out :
Which is simplified to :
Or, even more conveniently :
alright let's break it down.
if we had
we would factorise it by taking 2x out of the equation.
So we divide all terms by 2x:
So same as
we can take 2 out of the equation;
So divide everything by 2
you will get:
I divided the -4 by 2 (which made -2) and 2 by 2 ( which made 1)
Is this more clear now?