(f○g)(x)=f(g(x))
(f○g)(x)=6(4x+1)
(f○g)(x)=24x+6
You already got the first two questions right: the group with the highest number of people unemployed / unemployment rate is the one with the highest bar in the respective histogram.
The two graph are related in this sense: take the first age group as reference. We know that 700 people from 16 to 19 are unemployed, and that those people represent 14% of the population, then we know that the 14% of the population between 16 and 19 is 700.
We can deduce that, if x is the number of people between 16 and 19, we have

So, by the relation between the two graphs, we can deduce the total population for each age group.
Answer:
B. 1 and -2
Explanation:
First, add up the equations:
x-x+3y+y=4
4y=4
y=1
Now, plug y into any of the original equations above and solve for x:
-x+1=3
-x=2
x=-2
Therefore, the answer is B. 1 and -2
Answer:
B. 840
Step-by-step explanation:
21 is 70% of 30 and 70% of 1,200 is 840.
(p-8-m)/(-1+p)=1 1/9;p=1 7/8
(p+1)/(p+8+m)=1 1/9;p=1 7/8
1/(8+m)=10/9;p=15/8
that's as far as it can be solved