3. En una bolsa se tienen 5 tornillos de acero, 7 de titanio y 10 de silicio. Si se extraen 4 tornillos al arar, calaita probabilidad de que sean de acero a) Si se regresa cada tornillo antes de sacar el otro (5\%) b) Si no se regresa cada tornillo antes de sacar el otro

Find all exact solutions on the interval \( 0 \leq x<2 \pi \). If there is more than one answer, enter them as a comma separated list.

Divide and simplify. \[ \frac{x^{2}-14 x+49}{x^{2}-49} \div \frac{4 x-28}{x+7} \]

47delen elever som cyklar till skolan ökar frân \( 40 \% \) till \( 50 \% \). Hur stor âr ôkningen \( i \) \( \begin{array}{ll}\text { a) procentenheter } & \text { b) procent }\end{array} \)

(1.) Study this system of equations. \( \begin{array}{l}3 x+y=-3 \\ x-4 y=-1\end{array} \) (4) Which statement describes the solution to this system of equations. (A) There are infinitely many solutions. (B) There are no solutions. (C) There is exactly one solution at \( (-1,0) \). (D) There is exactly one solution at \( (-3,-1) \).

Of the valres made by a new procees, \( 10 \% \) are found to be defectire. The values are paked into boxes each containing 15 valves. Find the probability that a bux will contain at mest two defective