Question 1168485
slower travels at x km/min (note units) *12.4 min or 12.4x km
faster travels at (x+0.135)km/min and the 0.135 is 8.1 km/h converted to min.and its distance is 12.4(x+0.135)
or 12.4x+1.674 km
Those two describe 26 km in distance since the time is already considered.
12.4x+12.4x+1.674 km=26 km
24.8 x= 24.326 km
x=0.9809 km/min (not rounded from calculator).
multiply by 60 for x=58.85 or 58.9 km/h and x+8.1 =67 km/h, the answer being 58.9, 67, without units.

Check using hours
The two are approaching each other at 2x+8.1 km/h. In 12.4 minutes they meet, or 0.206667 hours.

that is the time for the combined distance to be 26 km, so the combined speed is 26/0.2066667 or 125.80 km/h

x+x+8.1=125.8
2x=117.7
x=58.85 km/h as above.