A reflex angle is the larger angle, it’s always more than 180* (half a circle) but less then 360* (a full circle).
6 (x + 5) = -36
6x +30 = -36 (distribute)
6x +30 (-30) = -36 -30
6x = -66
x = -11
In total, they would need 4 pumps. If we divide 55 by 17, we get just more than 3. This little more would need an entire pump. So the answer 4 total, 3 added