A ratio that compares two quantities measured in different units is a conversion factor!
$9147 x 12 =190,764
12 is how many months there is in a year
M = ( (-6+4)/2, (3+-2)/2 )
M = (-1, 1/2)
Use substitution
-x + 4 = 1/3x + 8
4 = 4/3x + 8
-4 = 4/3x
x = -4 * 3/4
x = -3
Then plug x into one of the original equations. In this case y = -x + 4 is the easiest.
y = -(-3) + 4
y = 7