The scatter plot shows the number of population P of town (in thousands) t years after 2000. Which is the best linear equation to model the town's population from 2000 to 2010?

x/3-10=8

x/3=18

x=48

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.

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times both sides by 2, times () by 8, add alile terms, move terms, add alike and caculate divide both sides by 3