Can any one confirm that I am not losing it on these 2 problems!?

Solve for x,

\(\displaystyle t=-6x^2+6x\)

I calculate \(\displaystyle x=\frac{-6\pm \sqrt{36-24t}}{-12}\) which i knw can be further reduced but the answer in the book is \(\displaystyle x=3\pm \sqrt{9-t}\) and

\(\displaystyle t=\frac{x^2}{2} + \frac{9}{2}-2x\)

I calculate \(\displaystyle x=\frac{4\pm \sqrt{-20+8t}}{2}\) but the answer in the book is \(\displaystyle x=2 \pm\sqrt{2t-5}\)

thanks