6x^2 + 9 - 14 = 5x^2 + 9x + 11

Combine like terms on the left side:

6x^2 - 5 = 5x^2 + 9x + 11

Move all terms to one side to form a quadratic equation:

x^2 - 9x - 16 = 0

Use the quadratic formula x = [-b ± sqrt(b^2 - 4ac)] / 2a, where a=1, b=-9, c=-16:

x = [9 ± sqrt((-9)^2 - 4*1*(-16))] / 2*1

x = [9 ± sqrt(81 + 64)] / 2

x = [9 ± sqrt(145)] / 2