Seven years ago,scott was 3 times as old as Kathy was at that time.If Scott is now 5 years older tha

题目

Seven years ago,scott was 3 times as old as Kathy was at that time.If Scott is now 5 years older than Kathy,how old is Scott?

答案

7年前,斯科特的年龄是凯西的3倍.如果现在斯科特比凯西大5岁,问斯科特现在多大?
y-7=3(x-7)
y=x+5
解方程组得y=14.5
斯科特14岁半