OKAAAAYY!!!! Now look at this mess how am i suppose to solve this

Vincente put his money into a mutual fund, where the amount of money he earned or lost can be found using the equation below, where M is the money Vincente earned or lost and x is time in years.

M = x2 - 8x - 109

If Vincente lost $100, how long did he have his money in the mutual fund?

1 year
9 years
8 years
10 years

Question

OKAAAAYY!!!! Now look at this mess how am i suppose to solve this


Vincente put his money into a mutual fund, where the amount of money he earned or lost can be found using the equation below, where M is the money Vincente earned or lost and x is time in years.

M = x2 - 8x - 109

If Vincente lost $100, how long did he have his money in the mutual fund?

    1 year
    9 years
    8 years
    10 years

anonymous · Answer

8 years

anonymous · Answer

you mean 9 years

anonymous · Answer

mainly because you have to Substitute M = -100 into the equation given, and solve for x

anonymous · Answer

i'll show you my way of doing it 

100	= x^2 - 8x - 109
0= x^2 - 8x - 9
0= (x + 1)(x - 9)

x + 1 = 0		x - 9	 = 0
x= -1		x= 9

anonymous · Answer

Since x represents time, and time cannot be negative, the solution x = -1 can be discarded

anonymous · Answer

So Therefore, Vincente left his money in the mutual fund for 9 years

anonymous · Answer

so are you sure its 8 years

jojo4eva · Answer

Ok hun look. How are you asking for help and then solving your own question lol. Im so weak right now im about to fall out my chair im laughing so hard lol

anonymous · Answer

no no im just asking for a response how other people see it @jojo4eva