14 + {-2 + 3[1 + 3(-6-2)]}
14 + { -2 + 3[1 + 3(-8)]}
14 + { -2 + 3[1 - 24]}
14 + { -2 + 3[-23]}
14 + {-2 - 69}
14 + {-71}
14 - 71
- 57 <==
The missing number is the square-root of the constant term on the left-hand-side, which equals sqrt(1/16)=1/sqrt(16)=1/4.
Check:
(x+1/4)^2=x^2+2*(1/4)x+(1/4)^2=x^2+x/2+1/16. ok
Answer: x= 1/4
