Determine which value is a solution to the open sentence. 3 + 6x = 21
a. 3
b. 18
c. 12
d. 4

Each quadrants' angle is 90 degrees. Rotating (x, y) -270 degrees would move it from quadrant I to quadrant IV. (x, y) = (+, +) = Quadrant I (-x, y) = (-, +) = Quadrant II (-x, -y) = (-, -) = Quadrant III (x, -y) = (+, -) = Quadrant IV Hope this helps. :)