$$ \begin{align*} \textbf{Izračunaj ove izraze } \\ &\ a) X^{2} - X \sqrt{X^{2}- 5 X+5} = 18 X ^{2}\\ &\ b) X^{2} - 18 x + \sqrt{x^{2}-2x+ 6 } = 0\\ &\ c) \binom{21}{x}\sum_{x}^{x+12} ( X+2X - 9 )\\ &\ d) X^{3} - 9 X - 9 \\ &\ Marko
Darko \end{align*} $$