Answer:
Hey There!
Let's solve...
Here it is a rectangular floor with length =21 cm and width =15cm
So

So now We need to convert it to yards square

So how this 9 ft^2 came??
Let's know

<h2>I hope it is helpful to you...</h2><h3>Cheers!_______</h3>
Answer: Second option.
Step-by-step explanation:
Let be "e" the number of easy puzzles Tina solved and "h" the number of hard puzzles Tina solved.
Set up a system of equations:

You can use the Eliminationn Method to solve this system of equations:
- Multiply the first equation by -30.
- Add the equations.
- Solve for "h".
Therefore, through this proccedure, you get:

Answer:
Step-by-step explanation:
d(t)=-2t^2+9t+18
calculate the derivate : f'(t) = - 4t+9
f'(t) = 0 : - 4t+9= 0 so t = 9/4
the maximum value is f(9/4) = ....... continue
The answer is C 41 because those two numbers are in the middle when arranging them