If that's plus 36, it factors to (x - 9)(x - 4) If it's minus 36, it gets ugly in a hurry.
x2 + 13x + 36 = (x + 9)(x + 4)
6(13x + 6)
(x + 4)(x + 9)
(x + 9)(x + 4)
The factors of x2-13x+36 are 'x-9' and 'x-4'because the expression (x-9)(x-4) can be simplified as x2-13x+36.
(x + 9)(x + 4)
(x-4)(x-9)
x2-13x+36 = (x-4)(x-9) when factored
x squared minus 12 x plus 36 = (x - 6)(x - 6)
x^2 - 13x + 36 = 0 Factor: (X-9)(X-4) = 0 X = 9 X = 4
x2 + 13x + 36 = 0 so (x+4)(x+9) = 0 so that x = -4 or x = -9