Mathematics

Problem

For

f\!:\!\mathbb Z \to \mathbb Z

defined by

f(x)=3x+2

, which statement is true? a)

f

is not onto, because

3x+2

always produces an even integer and hence misses all odd integers. b)

f

is not onto, because there exist integers

y

for which

(y-2)/3

is not an integer. c)

f

is not onto, because it is not one–one. d)

f

is onto, because for every integer

y

x=(y-2)/3

is an integer.