we have

Group terms that contain the same variable, and move the constant to the opposite side of the equation

Factor the leading coefficient
----------> the value of A is 
Complete the square. Remember to balance the equation by adding the same constants to each side


Rewrite as perfect squares


therefore
the answer is
the value of A is 
Answer:
Step-by-step explanation: The student divided the number of wins by the number of losses.
The student should have divided the number of wins by the total number of games.
The student should have first added 20 and 10 to find that there were a total of 30 games.
-1 is the opposite reciprical (perpendicular)
Answer:
It is proved that
exixts at (0,0) but not differentiable there.
Step-by-step explanation:
Given function is,

- To show exixtance of
we take,
exists.
And,
exists.
- To show f(x,y) is not differentiable at the origin cheaking continuity at origin be such that,
where m is a variable.
which depends on various values of m, therefore limit does not exists. So f(x,y) is not continuous at (0,0). Hence it is not differentiable at (0,0).