In 2007, there were more than 8.14 million cars for sale. The number of cars then decreased by 23% per year. Write an exponential growth or decay model given by the number of c cars over t years after 2007. Use this model to estimate how many cars there were in 2013?

In 2013 there were approximately 2.2 million cars for sale.

Step-by-step explanation:

Since the number of cars is decreasing by 23% per year, it is a decay model. This types of decay can be expressed in the following expression:

Where x is the year, cars(2007) is the number of cars in 2007. Applying this data we have:

If we want to know the number of cars in 2013, we need to apply that value to x and solve the expression.

In 2013 there were approximately 2.2 million cars for sale.

the answer is:

the answer is:

to solve the problem, we need to remember the quotient of power property, it's defined by the following relation:

if we have a quotienf of powers that have the same base, we need to keep the same base and subtract the exponent of the denominator power to the exponent of the numerator power.

so, we are given the expression:

then, calculating we have:

hence, the answer is:

have a nice day!

mr. india