In functions, what does (x+2)(x-4) equate to?

f(x) = x^2 -2x -8

Step-by-step explanation:

(x+2)(x-4)

FOIL

first: x*x = x^2

outer: -4x

inner: 2x

last: 2*-4x = -8

Add together

x^2 +2x-4x-8

x^2 -2x -8

This is a parabola

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.

what i would say the best answer is a. 40.5