what is the value of c so that x^2-11x+c is a perfect-square trinomial?

A.121
B.121/4
C.- 11/2
D.121/2

The value of c that makes x^2-11x+c a perfect-square trinomial is equal to half of the coefficient of x squared term squared. In this case, half of the coefficient of x is -11/2, so we need to square -11/2 to get the value of c.

(-11/2)^2 = 121/4

Therefore, the value of c that makes x^2-11x+c a perfect-square trinomial is B. 121/4.