Hi,
Quadratic functions in standard form
f(x) = a(x - h)2 + k where (h,k) is the vertex point
x^2-5x-6=0
completing the square by adding and subtracting (5/2)^2 = 25/4
f(x)= x^2-5x + 25/4 - 25/4-24/4
f(x)= (x - 5/2)^2 - 49/4
x^2-5x-6=0
solving by factoring
(x-6)(x+1) = 0
(x-6)=0
x = 6
(x+1) = 0
x = -1
Solution Set is {-1,6}