Answer:
y = 5 e^r * t
Let y be the population in billions and t the value of elapsed years
7 = 5 e^r * t is the equation being used where t = 15
7/5 = e^r * t
ln 7/5 = r * t taking ln of both sides
r = .336 / 15 = .0224
y = 5 e^(.0224 t) is then our equation
Check - suppose you want y at 2020
y = 5 e^(.0224 * 20) would be the equation
y = 5 e^.449 = 7.83 billion - seems to be a reasonable answer
Factoring – Using the Distributive Property. A factor is a number that can be divided into another number evenly. For example, the factors of 6 are 1, 2, 3, and 6. ... It means that a number outside the parentheses of an addition problem can be multiplied by each number inside the parentheses.
