###Exercise 1###
x <- 1
y <- 2
z <- 10
x + y + 2 * z
x*x / y + 3 * z #here I gave two examples

###Exercise 2###
space <- x + y + z
space <- sum(c(x, y, z)) #here I gave two examples

###Exercise 3###
n <- -4
n + x
abs(n) + x

###Exercise 4###
sequential_vector <- c(3:21)
sequential_vector <- seq(3, 21) #here I gave two examples
sequential_vector[2] * 3
sequential_vector * 4
length(sequential_vector) #to see how long the vector is for the following code. Pretending I am not working in Rstudio so I cannot see the environment
sequential_vector[1:18] * 5
sequential_vector[-19] * 5 #here I gave two examples

###Exercise 5###
three <- c(1, 2, 3)
three_hundred <- rep(three, 100)

###Exercise 6###
three_by_three <- matrix(c(rep(4, 3), 1:6), nrow = 3, byrow = F)
three_by_three[ ,colSums(three_by_three)>10]