Galilean transformation problem (Speed)

1. The problem statement, all variables and given/known data

A girl is riding a bicycle along a straight road at constant speed, and passes a friend standing at a bus stop (event #1). At a time of 60 s later the friend catches a bus (event #2)
If the distance separating the events is 126 m in the frame of the girl on the bicycle, what is the bicycle’s speed?

2. Relevant equations
u = u’ + v

3. The attempt at a solution
u = u’ + v
can be written as:
Δx/t = Δx’/t + v
v = Δx/t – Δx’/t
v = 0m/60s – 126m /60s
v = -126 m/ 60s
v = -2.1 m/s

Just wondering if the negative holds any significance? I know we’re talking about speed which is scalar but how come the calculation gives a negative?

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