The amount of money in a bank account increased by 21.5% over the last year. If the amount of money at the beginning of the year is represented by n, which expression represents the amount of money in the bank account after the increase? A: n + 0.215n
B: n + 21.5n
C: 0.215n
D: 21.5n

solution:

the given function is ,

      =

the three roots of this quadratic function is , 0 ,8 and 10.all the roots are real and rational.

if a quadratic equation is of the form ,

sum of the roots = a + b +c= 0+8+10=18=  

product of roots taken two at a time = a b + b c+ c a = 0+80+0=80 =  

product of roots = a b c = 0=  

there are 11 doors in a hall starting from 0 to 11.the entry in the hall is permitted through gate number 0 and exit is allowed through only gate number 8 and 10.so, three roots(0,8,10) of quadratic function is given by entry and exit route of this hall.

i think i remember taking that quiz.

a.

but im not sure so don't count on me.

the answer is a 7 in hope i you