Answer:
Add the area of the rectangle with the semicircle.
10x4 + 0.5(3.14)(25)
40+39.25
79.25
So the answer is C. 79.
Let me know if this helps!
Suppose you add x liters of pure water to the 10 L of 25% acid solution. The new solution's volume is x + 10 L. Each L of pure water contributes no acid, while the starting solution contains 2.5 L of acid. So in the new solution, you end up with a concentration of (2.5 L)/(x + 10 L), and you want this concentration to be 10%. So we have

and so you would need to add 15 L of pure water to get the desired concentration of acid.
Answer:
Step-by-step explanation:
It would be the area of the big square minus the area of the small square.
Answer: the answer is 180 
Step-by-step explanation:
Area of a rectangle multiply length times base. 15 x 12 = 180. Hope this helps!