(x^2 - 6x)^2 - 50(x^2 - 6x) - 275 = 0
Let u = x^2 - 6x. We have:
u^2 - 50u - 275 = 0
(u - 55)(u + 5) = 0
u = 55 or u = -5
When u = 55, we have:
x^2 - 6x = 55
x^2 - 6x - 55 = 0
(x - 11)(x + 5) = 0
x = 11 or x = -5
When u = -5, we have:
x^2 - 6x = -5
x ^2 - 6x + 5 = 0
(x - 1)(x - 5) = 0
x = 1 or x = 5
Hence, the solutions are x = -5, x = 1, x = 5 and x = 11