(1000 – 775): (85:17)
72:18: (732 – 539)
92 : 23 - (102 + 25)
846 : (93:31​

(1000 – 775): (85:17) = 45

72:18: (732 – 539) = 4/193

92 : 23 - (102 + 25) = - 123

846 : (93:31) = 282

x/3 + 1/2(2x/3) + 15 = x

x/3  + x/3 +15 = x

2x/3 + 15 = x

15 = x - 2x/3 =x/3

x = 15*3 =45

6+4=10 км/ч скорость сближения