1a

(5*4)^(4*5)-56
## [1] 1.048576e+26

1b

23-1*(8-12)
## [1] 27

1c

56/8*(3+4)
## [1] 49

1d

45-5*8+(8+9)
## [1] 22

2a

a <- c(2, 5, 6, 7)
a
## [1] 2 5 6 7

2b

b <- c(1, 0, 9, 8)
b
## [1] 1 0 9 8

2c

c <- c(6, 5, 8, 3)
c
## [1] 6 5 8 3

Matrix

matrix_Z <- matrix(c(a, b, c), byrow = TRUE, nrow = 3)
matrix_Z
##      [,1] [,2] [,3] [,4]
## [1,]    2    5    6    7
## [2,]    1    0    9    8
## [3,]    6    5    8    3

Column & Row Titles

Column_title <- c("Mon", "Tue", "Wed", "Thu")
Row_title <- c("Present", "Absent", "On Leave")
colnames(matrix_Z) <- Column_title
rownames(matrix_Z) <- Row_title
matrix_Z
##          Mon Tue Wed Thu
## Present    2   5   6   7
## Absent     1   0   9   8
## On Leave   6   5   8   3

Column & Row sums

rowSums(matrix_Z)
##  Present   Absent On Leave 
##       20       18       22
colSums(matrix_Z)
## Mon Tue Wed Thu 
##   9  10  23  18