Answer: C. 20 inches
Step-by-step explanation:
perimeter= 2 x (4+6)=20 inches
Answer:
-3x+30
Step-by-step explanation:

Expand 

Simplify 

Since, population of species A is represented by : 
Let us find the population of species A, at the end of week 1:
i.e., x = 1
i.e., 
i.e., 
i.e., 
Also, since population of species B is represented by : 
Let us find the population of species B, at the end of week 1:
i.e., x = 1
i.e., 
i.e., 
i.e., 
Thus, at the end of 1 week, species A and species B will have the same population.
Hence, option D is correct.
The gas would have cost $19.50. Hope this helps :)