4. ¿Cuál de las siguientes expresiones es equivalente a la operación \( 12^{3} \cdot 13^{3} \) ?

Resolver \( \left\{\begin{aligned} x+2 y+z & =4 \\ 3 x+z & =2 \\ x-y+z & =7\end{aligned}\right. \)

Simplify the expression \( 9 j-j+8 j \)

Simplify. \[ \frac{x^{2} y^{6}}{x^{3} y^{6}} \]

Which of the following equations represents a line that passes through the points \( (-4,11) \) and \( (6,-9) \) ? \[ \begin{array}{l}\text { I. } y=-2 x+3 \\ \text { II. } y+9=-2(x-9) \\ \text { Answer } \\ \text { Neither } \\ \text { II only }\end{array} \] I only I II

Simplify. \[ \frac{a^{5} b}{a^{4} b^{7}} \]