<u>ANSWER</u>
A. (4,12)
<u>EXPLANATION</u>
The equations are:

and

To eliminate a variable we make the coefficients of that variable the same in both equations.
It is easier to eliminate x.
We multiply the first equation by 2 to get:

We add equations (2) and (3).


Divide both sides by 23


Put x=4 into equation (1).






The solution is (4,12)
I assume there are some plus signs that aren't rendering for some reason, so that the plane should be

.
You're minimizing

subject to the constraint

. Note that

and

attain their extrema at the same values of

, so we'll be working with the squared distance to avoid working out some slightly more complicated partial derivatives later.
The Lagrangian is

Take your partial derivatives and set them equal to 0:

Adding the first three equations together yields

and plugging this into the first three equations, you find a critical point at

.
The squared distance is then

, which means the shortest distance must be

.
Answer:
i√19
Step-by-step explanation:
Because √(-19) = √(-1)√19, and because √(-1) = i, we get i√19
49/9=m/n this is because you multiply by the reciprocal of 3/7