x^3 + 2x(2x-1) + 26 = 5x(x^2 - 3) - (2x)^2 (x-1)
=> x^3+4x^2-2x+26=5x^3-15x-4x^3+4x^2
=>x^3+4x^2-2x+26=x^3-15x+4x^2
=>-2x+26=-15x
=>13x=26
x=2