Answer:
First answer: "Add the exponents"
Step-by-step explanation:
The laws of exponents include the following for product of exponents with the same base:

which implies addition of exponents
So you need to add exponents
The selling price would be $11.20.
40% = 40/100 = 0.4
The mark up is 40% of the cost; this means 40% of 8:
40% of 8 = 0.4(8) = 3.20
8 + 3.20 = 11.20
Answer:
is it 7
Step-by-step explanation:
Answer:
Davide's age is 10.
L'età di Davide è 10.
Step-by-step explanation:
The average age of Aldo, Bruno, Carlo and Davide is 16 years.
I am going to say that:
x is Aldo's age.
y is Bruno's age.
z is Carlo's age.
w is Davide's age.
Average of the 4 is 16 years.
This means that:


If we do not consider Davide, the mean is 18. So


Replacing in the first equation:



Davide's age is 10.
L'età di Davide è 10.