1,2*R + c*2π*10700/60 =7,2 | * 8
8*R + c*2π*8950/60 =7,2 | * 1.2
9.6*R +c*8964 = 57.6
9.6*R +c*1124.7= 8.64 | abziehen
----------------------------
c*8964 - c * 1124.7 = 57.6 - 8.64
c * 7839.3 = 48.96
c = 0.006245
Einsetzen in
9.6*R +c*8964 = 57.6
9.6*R +0.006245*8964 = 57.6
9.6R = 1.616
R = 0.168