Alexis sold half of her dolls and then bought six more dolls. She now has twelve dolls how many dolls did Alexis begin with ?

Please explain the answer and not just give the answer .

12

Step-by-step explanation: Because 12 old dolls - 6 dolls = 6 dolls. Then you add 6 old dolls and 6 new dolls and you get 12 old and new dolls. Sorry  if this is confusing. I tried to make it less confusing.

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.