What number would you add to the equation below to complete the square? x2 - 5x = 0?

Given that x^2-5x=0, to solve it using the complete square method, we need the value of c. The quadratic equation is in the form of:

ax^2+bx+c=0

to get c we use the formula:

c = (b/2a) ^2

b=-5

a=1

thus

c = (-5/2*1) ^2

c=25/4

the number that should be added is 25/4