Answer: A
Step-by-step explanation:
Only the first scatterplot has the first data point correctly plotted.
Let
. The tangent plane to the surface at (0, 0, 8) is

The gradient is

so the tangent plane's equation is

The normal vector to the plane at (0, 0, 8) is the same as the gradient of the surface at this point, (1, 1, 1). We can get all points along the line containing this vector by scaling the vector by
, then ensure it passes through (0, 0, 8) by translating the line so that it does. Then the line has parametric equation

or
,
, and
.
(See the attached plot; the given surface is orange, (0, 0, 8) is the black point, the tangent plane is blue, and the red line is the normal at this point)
Side BC is congruent to side BC.
Using the congruent angles and the angle bisectors, you can get two angles congruent to two other angles, so you use ASA to prove the triangles congruent. Then you use CPCTC to prove the sides congruent.
Answer: C.) ASA
The answer is x = 2 and y = 3