Answer:

Step-by-step explanation:
"At least" is inclusive, so you can be 21 years old.
Answer:
36
Step-by-step explanation:
Substitute the A for the 9, since A=9, and multiply the numbers
X = 4 ; x = 3 + i ; x = 3 - i
(If you get a zero that is adding or subtracting, you always need to write it twice but change the sign do they cancel out)
f(x) = (x-4)(x-3-i)(x-3+i)
Distributing the last two parenthesis first is always the best way to start off
(x-3-i)(x-3+i) has (x-3) in common so it can be separated to
(x-3)^2 + (-i)(+i)
(x^2 - 6x + 9) ; (-i)(+i) is always +1
(x^2 - 6x + 9) + 1
(x^2 - 6x + 10)
Now multiply this with (x-4)
x^3 - 6x^2 + 10x
- 4x^2 + 24x - 40
x^3 - 10x^2 + 34x - 40 = f(x)
(10x + 4) + (5x-4) ≈ 180
solve for x and you get x≈12
plug 12 in to 5x-4 and you get 56
eight million, four hundred and nine thousand, one hundred and twenty