Answer:

Step-by-step explanation:
The exponential function that decrease by 15% every time x increases by 1 is given by:

We simplify the parenthesis to get:

Therefore the decrease by 15% every time x increases by 1 is

The second choice is correct.
Answer: 500 miles
Step-by-step explanation:
Given : Sergio and Lizeth have planned to rent a car from a company that charges $75 a week plus $0.25 a mile.
i.e. Fixed charge= $75
Rate per mile = $0.25
Let x denotes the number of miles.
Then, Total charges = Fixed charge+ Rate per mile x No. of miles traveled
= $75+ $0.25x
To keep budget within $200, we have following equation.

Hence, they can travel 500 miles and still keep within their $200 budget.
Answer:
<em>Scott will take 221 minutes to run 52 km</em>
Step-by-step explanation:
<u>Speed</u>
The speed of an object can be calculated with the formula:

Where d is the distance traveled and t is the time taken.
Scott can run d=20 km in 85 minutes. Thus, his speed is:

Now he wants to know how many minutes it will take him to run d=52 km. Solving the formula for t:

Since the speed has been already determined:

Multiplying by the reciprocal of the denominator:

t = 221 min
Scott will take 221 minutes to run 52 km
Answer:
Value of expression in single logarithm is
.
Step-by-step explanation:
Given expression is,

Now using logarithmic rule to solve the expression as follows,
Applying product rule of logarithmic,

Therefore,

Applying power rule of logarithmic,

Therefore,


Applying quotient rule of logarithmic,

Therefore,

Simplifying,



Therefore value of expression is 
I hope this helps you
Area =base.height
246=base.20,5
base=12