In the list 2,x,y,5, the sum of any two adjacent numbers is constant. What is the value of x−y?
A number or a short expression. Fractions can be typed as 3/2, and spacing doesn't matter.
Solution
Since the sum of any two adjacent numbers is constant, then 2+x=x+y. This means that y=2 and makes the list 2,x,2,5. This means that the sum of any two adjacent numbers is 2+5=7, and so x=5. Therefore, x−y=5−2=3.
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