I'm assuming that the lower case c and the upper case C are the same variables.
6C^2 + 2.5D - D + 2C^2 - 3D = 8C^2 - 1.5D
Answer:

Step-by-step explanation:
<u>Step 1: Determine the area of the left rectangle</u>
We can tell that the total shape seems like two rectangles glued together. We can separate the left rectangle and determine the area of it and then determine the area of the right rectangle and combine them. Lets first solve the left rectangle.



<u>Step 2: Determine the area of the right rectangle</u>



<u>Step 3: Determine the total area</u>



Answer: 
The easiest way to do this is to pick your prime numbers and multiply them to get the composite number.
13* 5*5*5 *2*2= 6500
Final answer: 6500