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⟩

Plz answer asap! i will reward brainliest and 12 points for these three questions!take notice: these three questions are completely different! 1) what is the percentage of sugar in the syrup made of 10 kg of water and 4 kg of suugar? 2) what was the original price if after 10% discount it became $450? 3) at first a price was decreased by 12%, then it was disounted again by an additional 5%. what is the percent of the total discount? , and remeber i will award brainliest and 12 points!