
Bradford T. answered 01/17/21
Retired Engineer / Upper level math instructor
x2-12x + 144 = x2-12x +36 -36 + 144 = (x-6)2 +108
x = 6 ± √-108 = 6 ± (6√3) i
(x+6 + (6√3) i)(x+6 - (6√3) i)
I don't see why they call it a perfect square trinomial unless the original expression is wrong.
A perfect square trinomial would be:
x2-24x + 144
For a perfect square trinomial ax2+bx+c, b2 must equal 4ac, which it is not for the original equation.