Answer:
Step-by-step explanation:
Any time you have compounding more than once a year (which is annually), unless we are talking about compounding continuously, you will use the formula

Here's what we have:
The amount after a certain time that she has in the bank is 4672.12; that's A(t).
The interest rate in decimal form is .18; that's r.
The number of times the interest compounds is 12; that's n
and the time that the money is invested is 3.5 years; that's t.
Filling all that into the formula:
Simplifying it down a bit:
Raise 1.015 to the 42nd power to get
4672.12 = P(1.868847115) and divide to get P alone:
P = 2500.00
She invested $2500.00 initially.
(a) 28%
(b) 24%
When calculating the total amount of people it come out to 150.
According to the table 42 people smoke. 42/150 is 28%
According to the table 36 people exercise regularly. 36/150 is 24%
F(x) = x² + x - 20 = x² + 5x - 4x - 20 = x(x + 5) - 4(x + 5) = (x + 5)(x - 4)
f(x) = 0 ⇔ (x + 5)(x - 4) = 0 ⇔ x + 5 = 0 or x - 4 = 0 ⇒ x = -5 or x = 4
Answer: C. x = -5 and x = 4.