Use the quadratic function \( f(x)=2 x^{2}+4 x-9 \) to answer the following questions. d) Find any \( x \)-intercepts. Select the correct choice below and, if necessary, fill in the answer box within your choice. A. \( x=\square \) (Type an exact answer, using radicals as needed. Use a comma to separate answers as needed.)

(Express \( \frac{6}{7 h}-\frac{3-4 g}{14 h} \) as a single fraction in its simplest form. Ungkapkan \( \frac{6}{7 h}-\frac{3-4 g}{14 h} \) sebagai pecahan tunggal dalam bentuk termudah.

f) \( (-15 a b c+12 a b-9 a c-3 a) \div(-3 a) \)

3.18. Determine el máximo comun divisor de los enteros \( 15,18,24 \) y escríbalo como una combinación lineal de \( 15,18,24 \). 3.19. Sea \( a \in \mathbb{Z}^{+} \)tal que \( \operatorname{mcd}(240, a)=1 \), probar que \( 240 \mid a^{4}-1 \).

expunencial \( \left.\left(4^{2}\right)\left(2^{3}\right)^{2 x-5}\right)=8 \)

-простіть вираз: \( \begin{array}{ll}15 \mathrm{~m}^{2} \cdot\left(4 \mathrm{~m}^{3}\right)^{2} ; & \text { 2) }-0,5 \mathrm{~m}^{5} \cdot\left(2 \mathrm{~m}^{3}\right)^{4} \\ \left.-3 \mathrm{a}^{3} \mathrm{~b}^{4}\right)^{4} \cdot\left(-\frac{1}{8} a^{3} b\right) ; & \text { 4) }\left(-\frac{4}{5} m n^{4}\right)^{3} \cdot 25 m^{4} \mathrm{n}\end{array} \)