Question

Ashley's monthly savings may be modeled by the function
, where
represents the amount of money Ashley saves in a month and
represents the number of months that have passed since she started saving money.

Which statements are true? Select two that apply.

function is f(x) = -2x^2 + 14x + 120

a: zeros represent months ashley saved 0
b: most money she made was 0
c: only reasonable zero is x = 5
d: only reasonble zero is x = 12
e: only reasonable zero is x = 120

select two

Answer 1

Answers: a and d.

Explanation: f(x) = -2x^2 + 14x + 120 has zeros at x = 12 and x = -5. Zeros mean f(x)=0, i.e. months she saved $0 (so a is true). A negative month is not reasonable, so the only reasonable zero is x = 12 (d is true).