Answer:
15.
16. 10 ml of 20% saline and 40 ml of 10% saline
Step-by-step explanation:
A chemist takes x ml of 20% saline and y ml of 10% saline. In total, he takes
x + y ml that is 50 ml, so
There are 
ml of salt in x ml of 20% saline and 
ml of salt in 10% saline. There are 
ml of salt in 50 ml of 12% saline. Thus,
15. We get the system of two equations:
16. Solve this system. From the first equation:
Substitute it into the second equation:
D, Each x value has one and only one y value.; This is because if an x-value repeats itself then it is not a function. You can test this on a graph by drawing a vertical line on it. If the vertical line intercepts the line more than once anywhere on the graph, then it is not a function.
The average intake rate is (21,340 animals)/(52 weeks) ≈ 410.4 animals/week
Z=180º-(62º+95º)
Z=180º-157º
z=23º
The Answer is C, my good friend.
