Let
x--------> the speed of the girl in step
y--------> the speed of the escalator in step
d------> the distance between ground and floor.
we know that
when the girl is going up on escalator
----> equation 
when the girl is going down on escalator
-------> equation 
Adds equation and equation
--------> equation 
Time to climb (in step) with y=0 (escalator standing still)
-----> equation 
Substitute equation in equation
therefore
the answer is
Answer:
Step-by-step explanation:
We can calculate probability by looking at the outcomes of an experiment or by reasoning about the possible outcomes.
Multiplied by three is the answer
Finding the slope, you get (-1-(-5))/(3-0)=4/3. For finding the slope, you can also just count the rise and the run, then divide them. For exampe, (3,-1) is 4 units higher and 3 units to the left, so the slope is 4/3. Also, looking at the graph shows you that the y-intercept is just (0,-5).
