Which pair of vectors is orthogonal? ⟨3, –5⟩ and ⟨6, –10⟩
⟨2, –3⟩ and ⟨9, –6⟩
⟨–2, 3⟩ and ⟨–6, –4⟩
⟨–5, 4⟩ and ⟨–4, –2⟩

⟨3, –5⟩ and ⟨6, –10⟩

Step-by-step explanation:

⟨3, –5⟩ cross ⟨6, –10⟩ = 0

⟨2, –3⟩ cross ⟨9, –6⟩ = 15

⟨–2, 3⟩ cross ⟨–6, –4⟩ = 26

⟨–5, 4⟩ cross ⟨–4, –2⟩ = 26

⟨3, –5⟩ and ⟨6, –10⟩

60: 45 =12: 9 =4: 3 so the answer is 4: 3