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

If n is one the 4n is 4
N is 2 then 4n is 8
N is 3, 4n is 12
N is 4 then 4n is 16
Answer:
Option C)

Step-by-step explanation:
We are given the following in the question:
"-7 and a number 5 units to the right of -7"
The nubmer 5 units to the right of -7 will be:

The number line shows the two marked points.
As observed from the number line, we can write the inequality:

Thus, the correct option is
Option C)

Answer: 30 months
Step-by-step explanation:
Hi, to answer this question we have to write an equation:
Matthew's saving account money (1500) must be equal to the product of the amount he pays per month for the app subscription (20) and the number of months (x); plus the product of the amount he pays per month for the Italian restaurant subscription (30) and the number of months (x).
1500= 20x+30x
Solving for x:
1500=50x
1500/50 =x
30 months =x
Feel free to ask for more if needed or if you did not understand something