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
I'm absolutely certain that the answer is 2. (0,-4), (5,3), (-4,3), (3,2) because in a function, x does not repeat
<em>I hope this helps, love!</em>
Hello.
For every 3 eggs, 4 dozens of cookies could be made, it is a pattern. Follow the pattern to find out how much could be made with a dozen eggs.
3 eggs = 4 dozen (48)
6 eggs = 8 dozen (96)
9 eggs = 12 dozen (144)
12 eggs = 16 dozen (192)
A dozen eggs could make 192 cookies.
Assume every item you sold was a case.
You would've gotten : 48 x 10 = $480.
But in reality, you only got $350, so it's a $130 difference.
Replace 1 cell phone case with 1 t-shirt -> the difference go down 5 every time. (for example, if you sold 47 case and 1 t-shirt, the difference go from $130 to $125)
So, the amount of t-shirt you sold was 130 : 5 = 26 (t-shirts)
And, you sold : (350 - 26 x 5) : 10 = 22 (cases)
Recheck : 26 + 22 = 48 items, and 26 x 5 + 22 x 10 = 130 + 220 = 350.
