hi there mate!!!!

Solution:

let the zeroes be a and B.

now,

x^2+7x+12= 0

by Factorization method,

x^2+4x+3x+12= 0

x(x+4) +3(x+4) = 0

(x+4)(x+3)= 0

x=-4 or x= -3

now,

let a= -b+√b^2-4ac

2a

here,

a= 1, b= 7 and c= 12

a=-7+√(7)^2-4×1×12

2

a= -7+√49-48

2

a= -7+√1/2

a= -7+1/2= -6/2= -3

also,

B=-b-√b^2-4ac

2a

B= -7-1/2= -8/2= -4

hence,

a= -3 and B= -4.......(1)

now,

1 + 1 -2aB

a B

=1+ 1 -2(12)

-3 -4

now,

=1×(-4) +1(-3) -24

-3(-4) -4(-3)

=-4-3 -24

12

=-7/12-24

=-7-288/12

=-295/12 ........(final answer)