Q) Check whether :Z×Z→Z×Z (where Z is the set of integers) defined as f(𝑥,y)=(2y,3𝑥) is injective

Surjective Functions (and a Proof!) | Surjections, Onto Functions, Surjective Proofs

Surjective (onto) and injective (one-to-one) functions | Linear Algebra | Khan Academy