Hello from MrBillDoesMath!
Answer:
x + 9 and (x + ( i - 7)) are factors
Discussion:
If f(x) has roots -9 and 7-i then
f(x) = g(x)(x - (-9)) (x - (7-i)) ( g(x) is a polynomial of degree less than f(x))
That is, x + 9 and (x + ( i - 7)) are factors of f(x)
BTW: if the coefficients of f(x) are real (not stated in the Question) then the conjugate of 7-i, i.e. 7 + i, is also be a root.
Thank you,
MrB
Step-by-step explanation:
Total bars = 4 + 5 + 7 + 9 = 25
Probability of Reese bar = 7/25
Probability of milky way = 9/25
10 to 11 = 1 hr
11 to 12 = 1 hr
12 to 1 = 1 hr
total = 3 hours