X-y=11
2x+y=19
equations by elimination

x=10, y=-1

(10,-1)

Step-by-step explanation:

x-y=11

2x+y=19

Add these two equations together to eliminate y

x-y=11

2x+y=19

3x = 30

Divide each side by 3

3x/3 = 30/3

x = 10

Now we need to find y

2x+y = 19

2(10) +y = 19

20+y =19

Subtract 20 from each side

20-20 +y = 19-20

y= -1

The correct answer is:

B) Statement 1 and Statement 2 are theorems because they can be proved with the help of appropriate postulates.

Explanation:

Statement 1 is the Line Intersection Theorem. To prove this, we use postulates about having only one plane passing through any 3 noncollinear points. We would choose two points from one line and one point from the second; they would be non-collinear points and be in one plane. This also works choosing the points the opposite way.

Statement 2 is the Point and Line Contained in Plane Theorem. Again, if two lines intersect, we can choose three points to define a plane. We have to prove that both lines are in the plane. We rely on previously proven postulates to do this.