6) x^-5x + 6 = 0

Rearranging the terms, we get x^2 - 5x + 6 = 0

This equation can be factored as (x - 2)(x - 3) = 0

Therefore, x = 2 or x = 3

7) 50x^2 + 4x - 54 = 0

This equation can be factored as (10x + 9)(5x - 6) = 0

Therefore, x = -9/10 or x = 6/5

8) 11x^2 - 10x - 21 = 0

This equation can be factored as (11x + 7)(x - 3) = 0

Therefore, x = -7/11 or x = 3