To find the missing number, we can use the fact that the sum of the solutions of a quadratic equation is given by the negative coefficient of the linear term divided by the coefficient of the quadratic term. In this case, the sum of the solutions is -14.
We are given that the solutions are 6 and 8. Therefore, we can calculate the sum of the solutions:
6 + 8 = 14
Since the sum of the solutions is -14, we can set up the equation:
14 + x = -14
Solving for x, we find:
x = -14 - 14
x = -28
Therefore, the missing number is -28.
The quadratic equation with solutions 6 and 8 is:
x^2 - 14x - 28 = 0