Answer:
The answer is 10a
Step-by-step explanation:
Combine like terms first
a+2a+3a+4a
=(a+2a+3a+4a)
Since all of these numbers have the same variable they can all be added up to get a sum of 10a which is its simplified form.
If you multiply 13.99x0.04=.5596
then you added
13.99+.5596=14.5496
And this is your answer
221,000,000,000,000,000,000 = 2.21 x 10^20
therefore, the answer is b
the answer should be 7/6