Circumference of circle= 2*idonthaveapisymbol*r
2pir
Or
Pi x diameter = 3.14 * 20
2(3.14)(10)
We want to use a matrix to solve
-8x - 8y = -16
6x - 9y = -108
Before solving, simplify the equations as follows:
Divide the first equation by -8 to obtain
x + y = 2 (1)
Divide the second equation by 3 to obtain
2x - 3y = -36 (2)
In matrix form, the equations are

The determinant of the matrix is
D = (1)(-3) - (1)(2) = -5
Use Cramer's Rule.

Similalrly,

Answer: (-6, 8) or x = -6, y = 8
Draw a number line from -10 to +10 with tick marks (division lines) every 1 unit. Now find the origin (in the middle of the line you have just drawn). Now move your pencil point 3 units to the left and plot a dark (closed) dot there. Then draw a ray from that closed dot to the left. Apparently we cannot extend that ray beyond -10.
(-10,-3] would be my representation of this situation.
Angle 1 = 130°
Angle 2 = 124°
Angle 3 = 56°
Angle 4 = 52°
Angle 5 = 72°
Angle 6 = 94°
I primarily used the triangles to get my answers. Remember the angles in a triangle add up to 180°.