Choose the correct description of the graph of the compound inequality: x − 1 less than or equal to 7 or 2x greater than or equal to 22 a number line with an open circle on 8, shading to the left, and an open circle on 11, shading to the right a number line with an open circle on 8, an open circle on 11, and shading in between a number line with a closed circle on 8, a closed circle on 11, and shading in between a number line with a closed circle on 8, shading to the left, and a closed circle on 11, shading to the right

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.