Question 815078
I am giving help on your SECOND question because it requires more thorough skill than the FIRST question.  


Factorize a -2 on the right side expression!
{{{-2(x^2-3x-1)}}}
NOW you are ready to complete the square, as long as you can identify the needed square term.  Focus on the trinomial factor of {{{x^2-3x-1}}};
The missing square term is {{{highlight((-3/2)^2=9/4)}}}, and THAT is the term you both add and subtract INSIDE the parentheses.


{{{f(x)=-2(x^2-3x-1 +9/4 -9/4)}}}
{{{f(x)=-2(x^2-3x+9/4 -1-9/4)}}}
{{{f(x)=-2((x^2-3x+9/4)-1-9/4)}}}
The grouping added is to emphasise,
{{{f(x)=-2((x-3/2)^2-4/4-9/4)}}}
{{{f(x)=-2((x-3/2)^2-13/4)}}}
And now perform the remultiplication to reverse the previous factorization.
{{{highlight(f(x)=-2(x-3/2)^2-13/2)}}}


Further, you might want to show {{{13/2}}} as {{{6&1/2}}}