问答题 If Alan gives Brenda $5.50, they will both have the same amount of money. If Brenda gives Alan $1.50, Alan will have twice as much as Brenda. What did they have at the start?
【正确答案】Alan $26.50; Brenda $15.50.
【答案解析】(假设Alan最初有x美元，Brenda最初有y美元，可得方程组 ①x-5.50=y+5.50 ②2(x-1.5)=y+1.5。方程可解，x= 26. 50，y=15. 50)