Answer:
the first one is right but the second one is -2 , not 2.
Step-by-step explanation:
Answer:
The value in millions of dollars of a downtown office building that cost 12 million dollars to build 20 years ago and depreciated at 9% per year is $1819738.95
Step-by-step explanation:
Cost of building 20 years ago = 12000000
We are given that the cost depreciated at 9% per year
Formula : 
Where N(t)= Population after t years
=Initial population=12000000
r= rate of depreciation=0.09
t = 20 years
Substitute the values in the formula:

N(t)=1819738.95
Hence the value in millions of dollars of a downtown office building that cost 12 million dollars to build 20 years ago and depreciated at 9% per year is $1819738.95
Answer:
40
Step-by-step explanation:
To solve this, we can create an equation that represents this situation. Since Christopher score 7 more than twice what Mathew scored, the equation will be:
C = 2M + 7
(Variables are representative of the first letter of each name)
Seeing as Christopher scored 87, we can put that into the equation and solve for M.
So, the equation will be:
87 = 2M + 7
Subtract 7 from both sides in order to isolate variable M on the right side.
80 = 2M
Now solve for M, which is 40 (divide both sides by 2).