Last month, Margo bought a tree that grows 2.5 \text{ cm}2.5 cm2, point, 5, start text, space, c, m, end text each day. It was 5 \text{ cm}5 cm5, start text, space, c, m, end text tall when she bought it and now it is 65 \text{ cm}65 cm65, start text, space, c, m, end text tall. Write an equation to determine the number of days (d)(d)(, d, )Margo has owned the plant. Find the number of days Margo has owned the plant.

i do not know the answer i am sorry

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.