Find the sum of the smaller root of x and z?

Directions (1 - 5): Read the questions carefully and answer the questions given below.

I) x2− (a + b)x – (192+ 53) = 0

II) y2 + (a * b)y – (212 - 50) = 0

III) z2 + (a3 + b3 + c - 4)z + (d2 - 137) = 0

Note:

(a - b) = 1 and sum of the squares of ‘a’ and ‘b’ is 13 and a and b are positive numbers.
Difference between the value of ‘c’ and ‘d’ is (a * b).
Value of c and d are consecutive prime number (less than 50) and the value of d is more than 25 and the value of c is less than 30.