Solve х2 - x - 12 = 0

Step-by-step explanation:

Once in standard form, identify a, b, and c from the original equation and plug them into the quadratic formula.

2 −  − 12 = 0

= 1

= -1

= − 12

= −( −1) ± √ ( −1)2 − 4⋅1 ( −12)

                       2.1

i believe the answer is letter c) 8

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.