He could use the mode of 89.
Y - x = 6
y + 2x = 57
2y - 2x =12
y + 2x = 57
∴3y = 69
y = 23
23 - x = 6
-x = -17
x =17
large van = 23
small van = 17
(-8, -11) because the points are just the opposite sign when reflecting over the x-axis
Aerobic, it uses oxygen for a longer period of time.