<u>Answer:
</u>
Expression x + 2my + z represents cost of order where x, y, z are cost of small , medium and large drinks (in dollars) respectively.
<u>Solution:
</u>
Given that
Juan’s family ordered a small drink and m medium drinks.
Alex family ordered m medium drinks and a large drink.
Need to write an algebraic expression which shows total cost of both order in dollars.
Let’s assume cost of one small drink = x
And assume cost of one medium drink = y
And assume cost of one large drink = z
So now cost of order of Juan’s family is equal to cost of 1 small drink + cost of m medium drinks = 1
x + m
y
= x + my
And cost of order of Alex family is equal to cost of m medium drinks + cost of one large drink
= m x y + 1 x z
=my + z
So total cost of both order in dollars = x + my + my + z = x + 2my + z
Hence expression x + 2my + z represents cost of order where x , y , z are cost of small , medium and large drinks (in dollars) respectively.
We have been given a graph of function g(x) which is a transformation of the function 
Now we have to find the equation of g(x)
Usually transformation involves shifting or stretching so we can use the graph to identify the transformation.
First you should check the graph of 
You will notice that it is always above x-axis (equation is x=0). Because x-axis acts as horizontal asymptote.
Now the given graph has asymptote at x=-2
which is just 2 unit down from the original asymptote x=0
so that means we need shift f(x), 2 unit down hence we get:

but that will disturb the y-intercept (0,1)
if we multiply
by 3 again then the y-intercept will remain (0,1)
Hence final equation for g(x) will be:

310 - 220 = 90
90/310 = x/100 (cross multiplication)
9000 = 310x
9000/310 = x
x = around 29%
"-y (less than or greater than sign) 136" translates into two separate inequalities:
-y < 136 and -y > 136.
You want to solve for y in each case. To do this, multiply each inequality by "-1" and then immediately change the direction of the inequality sign.
For example: -1(-y < 136) => y > -136.