\( 0,070 km = 70,10 cm \)

Wyatt's energetic Uncle Bob loves roller coasters, and he wants to ride them all! One day, Wyatt prints out a list of all the roller coasters in the United States. After reading it with Uncle Bob, they discover he has already ridden 88 of the coasters. There are still 405 coasters left to ride. Which equation can you use to find the total number of roller coasters c on Wyatt's list? \( c+88=405=405 \quad \frac{c}{88}=405 \) Solve this equation for \( c \) to find the number of roller coasters on Wyatt's list.

Step 1.\ Please convert the (10)8 to decimal value? Step 2.\ Please convert the (1F)16\ \ to decimal value

18. Simplify: \( 36 \times \$ 0.84 \)

2. Sea \( A=\{a, b, c, d, e, f, g\} \). Es obligatorio \( c \) y escoge uno de los restantes, es decir, sólo contesta dos. Demuestra que a) \( R_{1}=\{(a, a),(b, b),(c, c),(d, d),(e, e),(f, f),(g, g),(b, a),(a, b),(a, c),(c, a)\} \) es reflexiva y simétrica sobre \( A \), pero no es transitiva, explica con claridad. b) \( R_{2}=\{(a, a),(b, b),(c, c),(d, d),(e, e),(f, f),(g, g),(b, a),(a, c),(b, c)\} \) es reflexiva y transitiva pero no simétrica. c) \( R_{3}=\{(a, a),(b, b),(c, c),(d, d),(e, e),(f, f),(g, g),(a, b),(b, a),(c, d),(d, c),(e, f),(f, e)\} \) es de equivalen- cia. d) Da las clases de equivalencia de \( R_{3} \).

63. Sabendo que o \( 6^{\circ} \) ano B tem 14 alunos com 10 anos e 21 alunos com 11 anos, determine o que se pede em relação ao total de alunos, regis- trando a fração irredutivel. a) Fração que os alunos com 10 anos representam. b) Fração que os alunos com 11 anos representam.