Answer:
Below.
Step-by-step explanation:
Part A: 
Part B: Degree = 2, Classification = Quadratic
Part C: The polynomial is closed because it is multiplied. You CANNOT close under division.
1. Line l; point P not on l.( Take a line I and mark point P outside it or on the line.So from point P there are infinite number of lines out of which only one line is parallel to line I. Suppose you are taking point P on line I, from that point P also infinite number of lines can be drawn but only one line will be coincident or parallel to line I.
2. Plane R is parallel to plane S; Plane T cuts planes R and S.(Imagine you are sitting inside a room ,consider two walls opposite to each other as two planes R and S and floor on which you are sitting as third plane T ,so R and S are parallel and plane T is cutting them so in this case their lines of intersect .But this is not possible in each and every case, suppose R and S planes are parallel to each other and Plane T cuts them like two faces of a building and third plane T is stairs or suppose it is in slanting position i.e not parallel to R and S so in this case also lines of intersection will be parallel.
3. △ABC with midpoints M and N.( As you know if we take a triangle ABC ,the mid points of sides AB and AC being M and N, so the line joining the mid point of two sides of a triangle is parallel to third side and is half of it.
4.Point B is between points A and C.( Take a line segment AC. Mark any point B anywhere on the line segment AC. Three possibilities arises
(i) AB > BC (ii) AB < BC (iii) AB = BC
Since A, B,C are collinear .So in each case 
Answer:
50 gallons 20%
50 gallons 30%
Step-by-step explanation:
If x is gallons of 20% moonshine, and y is gallons of 30% moonshine, then:
x + y = 100
0.20x + 0.30y = 0.25(100)
Solve the system of equations using substitution or elimination. Using substitution:
0.20x + 0.30(100 − x) = 0.25(100)
0.20x + 30 − 0.30x = 25
5 = 0.10x
x = 50
y = 50
50% of 10 is just half so half of 10 is 5
The answer is five