Aseagull flying 21 feet above sea level is expressed as t(plus)21 feet. a fish swims the same number of feet below sea level. if sea level is considered to be 0, express the distance that the fish is swimming.

h = -21 ft  

Step-by-step explanation:

Think of this as a vertical number line.

If sea level is zero and the seagull is flying 21 ft above the surface, the bird's height

h = +21 ft

If the fish is 21 ft below the surface, it is swimming at a level

h = -21 ft.

i dont know

step-by-step explanation:

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.