Giải các pt$a, 18x^2-18x\sqrt{x} -17x-8\sqrt{x} -2=0$$b, x^2-3x+1=-\frac{\sqrt{3} }{3}.\sqrt{x^4+x^2+1}$ $c, \sqrt{2-x^2} +\sqrt{2-\frac{1}{x^2}} =4-x-\frac{1}{x}$$d, 2x^2+\sqrt{1-x} +2x\sqrt{1-x^2} =1$$e, \sqrt[4]{17-x^8} -\sqrt[4]{2x^8-1}=1$$g, x+\sqrt{4-x^2} =2+3x\sqrt{4-x^2}$$h,\sqrt[3]{81x-8} =x^3-2x^2+\frac{4}{3}x-2$$l, \sqrt{5x^2+14x+9} -\sqrt{x^2-x-20} =5\sqrt{x+1} $