ESIGUALDADES CUADRATICAS \( \begin{array}{ll}\text { i. Resuelva las siguientes desigualdades } \\ \text { a) } x^{2}-6 x+8 \leq 0 & \text { b) }-2 x^{2}+1>0\end{array} \)

\( \begin{array}{ll}\begin{array}{l}\text { Crude oil may contain hundreds of different types } \\ \text { of hydrocarbons. Some examples include: }\end{array} & \begin{array}{l}\text { Identify each of the highighted materials as an } \\ \text { element, a compound, or a mixture, and explain } \\ \text { your reasoning. }\end{array} \\ \text { - Butane }\left(\mathrm{C}_{4} \mathrm{H}_{10}\right) & \\ \text { - Dodecane }\left(\mathrm{C}_{12} \mathrm{H}_{26}\right) & \\ \text { - Benzene }\left(\mathrm{C}_{6} \mathrm{H}_{6}\right) & \\ \text { Many common fuels, such as gasoline and } \\ \text { kerosene, are combinations of these substances } \\ \text { or others. When these fuels burn, they combine } \\ \text { with oxygen }\left(\mathrm{O}_{2}\right) \text { to produce carbon dioxide }\left\{\mathrm{CO}_{2}\right) & \\ \text { and water }\left(\mathrm{H}_{2} \mathrm{O}\right) \text {. }\end{array} \)

Simplify the expression. \( -5 d^{3}-d^{3} \)

Construct a truth table for the statement \( \sim(q \wedge r) \rightarrow(\sim p \wedge r) \).

1) \( \lim _{x \rightarrow 2} \frac{2 x+1}{2 x^{2}-3 x-2}= \)

Construct a truth table for the statement \( (q \rightarrow r) \leftrightarrow \sim p \).