Write the explicit formula for the geometric sequence.

a1 = -5 a2 = 20 a3 = -80

a. an = -5 • (-4)n

b. an = -5(-4)n-1

c. an = -4(-5)n-1

d. an = -5 • (4)n

James purchased a $205,000 home with a 30-year mortgage at 5.78%. if makes a $1500 monthly mortgage payment, how many months early will he pay off his mortgage? a. 180 months b. 224 months c. 127 months d. 136 months

Airline passengers arrive randomly and independently at the passenger-screening facility at a major international airport. the mean arrival rate is 10 passengers per minutes. compute the following probabilities. p(x = 4) p(x > 11)

Do some research and find a city that has experienced population growth. determine its population on january 1st of a certain year. write an exponential function to represent the city’s population, y, based on the number of years that pass, x after a period of exponential growth. describe the variables and numbers that you used in your equation.