Christiane runs for 2.5 kilometers every day. After 7 days, how many meters has Christiane
2 answers:
You might be interested in
Answer:
x = 14 days
Step-by-step explanation:
To answer the question, find a function that represents the payment mode of plan A and an equation that represents the mode of payment of plan B.
For Plan B the payment is constant every afternoon, $ 11.5 (or 1150 cents) so the equation to represent this form of payment is as follows:
A = 1150x (with units in cents)
This equation represents the line of a line of slope 1150, which passes through point (0,0). Where x is the number of days {1, 2, 3 ....}
In form of payment B, the amount of payment is doubled each day. And the first payment is 2 cents. Therefore this model is represented by an exponential base 2 equation of the form:
Where x represents the number of days, which is always greater than 0 {1, 2, 3, 4 ...}
To know in which day the salary will be approximately the same we equate both equations and we clear x.
A = B
It is a somewhat difficult equation to solve, so I recommend iterating to get a value where the function approaches 0 (when this difference is zero it means that the A and B salaries are the same).
Suppose
x = 13 days
cents
It is not equal to 0.
Let's try with x = 15
cents
Then the value that makes the function zero is between x = 13 and x = 15
Let's try with x = 14
cents = 2.84 $ difference. X = 14 is the whole number where functions A and B are closer together (the salary is approximately the same). Therefore the answer is
x = 14 days
Answer:
The solutions are x=1 and x=-2/3
Step-by-step explanation:
we have
Group terms that contain the same variable, and move the constant to the opposite side of the equation
Factor the leading coefficient
Complete the square. Remember to balance the equation by adding the same constants to each side
Rewrite as perfect squares
square root both sides