If \( 2 \mathrm{a}-\frac{1}{2 \mathrm{a}}=3 \) then \( 16 \mathrm{a}^{4}+\frac{1}{16 \mathrm{a}^{4}} \) is?

13. Para qué valor de " \( x \) " se cumple la siguiente igualdad: \( \frac{\sqrt{(a b)^{2} \cdot \sqrt[3]{c^{x}}}}{\sqrt[3]{a^{x} \sqrt[4]{\left(\frac{c}{b}\right)^{2}}}}=(a b)^{\frac{10}{9} ; a \neq b} \)

\( 7 \cdot 9 ^ { x ^ { 2 } - 3 x + 1 } + 5 \cdot 6 ^ { x ^ { 2 } - 3 x + 1 } - 48 \cdot 4 ^ { 4 ^ { 2 } - 3 x } = 0 \)

(3) If \( 8 x+y i=i^{-17}+24 \), where \( i^{2}=-1 \), then \( x-y=-1 \) \( \begin{array}{lll}\text { (a) } 2 & \text { (b) } 4 & \text { (c) }-4 \\ \text { (d) } 25\end{array} \)

Example Solve the equation \( 2 x^{2}+4 x-10=0 \) with error precision 0.05

(8) If \( L^{2} \) and \( L \) are the two roots of the equation : \( x^{2}+a x+8=0 \), then \( a=\ldots \ldots \ldots \) \( \begin{array}{llll}\text { (a) }-6 & \text { (b) } 6 & \text { (c) } 4 & \text { (d) } 8\end{array} \)