If using the method of completing the square to solve the quadratic equation x^2+14x-1=0, which number would have to be added to "complete the square"?

(a) (8%) compute the probability of an even integer among the 100 integers 1! , 2! , 3! , until 100! (here n! is n factorial or n*(n-1)*(n-2) *… 1) (b) (16%) compute the probability of an even integer among the 100 integers: 1, 1+2, 1+2+3, 1+2+3+4, …., 1+2+3+… + 99, and 1+2+3+… + 100

Can someone me out here number 4 plz

If x is 6, then 7x= a. 13 b. 42 c. 42x d. 76