what if d maths is done like dx?

L=km/h
When L=40,m=175,h=286,
(skipping the units)
40=k(175)/ 286
K=286(40)/175=2288/35
L=2288/35=250/50
L=114400/8750
L =13.1m

2 answers

there seems to be a typo 3 lines up from the end...

But the math looks good, sorta.
tanks