1. \( a=\{(4,5),(-4,5),(2,3),(-2,3)\} \) 2. \( b=\{(0,-1),(2,-3),(-5,1),(-4,5)\} \) 3. \( c=\{(1,4),(2,8),(3,12),(4,16) \), 4. \( d=\{(A, 5),(K, 9),(0,5),(2,9)\} \) \( x^{-1}= \) \( y^{\prime} \)

(1) RAZONAMIENTO. Escribir los términos que hacen ver- dadera la igualdad. \( \begin{array}{ll}\text { 28. }(2) \times(23)=\square & \text { 29. }(-8) \times(-9)=\square \\ \text { 30. } \square \times(-7)=-42 & \text { 31. } 3 \times \square=33 \\ \text { 32. } 9 \times \square=-27 & \text { 33. } \square \times(-3) \times(\square)=9 \\ \text { 34. }(-5)(-3) \times \square=45 & \text { 35. }(-9) \times \square \times(-1)=36 \\ \text { 36. } \square \times \square \times \square=81 & \text { 37. }(-1) \times \square \times \square=-18\end{array} \)

In the cost function below, \( C(x) \) is the cost of producing \( x \) items. Find the average cost per item when the required number of items is produced. \( C(x)=4.5 x+9,300 \) \( \begin{array}{lll}\text { a. } 200 \text { items } & \text { b. } 2000 \text { items } & \text { c. } 5000 \text { items }\end{array} \)

The lengths of the rectangle have been measured to the nearest tenth of a metre. Work out the following, writing down all the figures on your calculator display: a) The upper bound for the perimeter of the rectangle. b) The lower bound for the area of the rectangle. 15.8 m

dick and Pam are paid \( \$ 61.75 \) for their work. Nick worked 3.5 hours, and Pam worked 3 hours. They split the money Nick and Pam are paid \( \$ \square \) for each hour worked the amount of time each of them worked. How much is Nick's share of the money? Explain.

¿.Cuáles de las siguientes afirmaciones están relacio- nadas con un vector? a. Camino 2 km a lo largo de la playa. b. Camino 2 km al norte a lo largo de la playa. c. Salto desde un acantilado y entro en el agua desplazándome 10 km por hora. d. Salto desde un acantilado y entro en el agua desplazándome verticalmente a una velocidad de 10 km por hora.