The greatest common factor, or GCF, is quite self-explanatory. Between two numbers, you have to find the greatest number that can be divided by both numbers without any remainder. This is useful in solving addition and subtraction operations involving fractions. The technique to do this is to place the numbers to the right. Then, place the factors to the left. I'm gonna show the solution so that you can understand better.
4 | 12 28 24
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| 3 7 6
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Since all numbers can be divided by 4, you place it on the left side. Then, place the quotients on the next row below. Since, there is no more common factor, it ends with the 2nd row. Then, multiply all the left numbers with the numbers in the very last column.
GCF = 4×3×7×6
GCF = 504
My estimated answer for 1 is x=1.59 or x=-1.26 and my exact answer is (in word form) x= 1 plus or minus the square root of 73 over 6. my estimated answer for 2 is x=-0.34 or x=1.74 and my exact answer (in word form) is x= -7 plus or minus the square root of 109 over -10. I took a picture of my work and hopefully you can read it
If you flipped the graph y=x^2+2x-2 vertically, you would get the graph y=-(x^2+2x-2) this is True.
By definition, we have

So, we have to solve two different equations, depending of the possible range for the variable. We have to remember about these ranges when we decide to accept or discard the solutions:
Suppose that 
In this case, the absolute value doesn't do anything: the equation is

We are supposing
, so we can accept this solution.
Now, suppose that
. Now the sign of the expression is flipped by the absolute value, and the equation becomes

Again, the solution is coherent with the assumption, so we can accept this value as well.