Sam is older than alexis. The sum of their ages is 35. The difference between their ages is 15. How old is sam and how old is alexis

Question

Substitution 

Answer 1

S + A = 35

S - A = 15    add equations

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2S = 50

S = 25

 

A = 10

 

Sam is 25, Alexis is 10

Answer 2

Let Sam be x years old, and Alexis be y years old. Then we know that:

 

x + y = 35

 

We also know that x - y = 15

 

By the Elimination Method, we know that:

 

2x = 50

 

x = 25

 

If x = 25, then y = 35 - x = 35 - 25 = 10

 

So Sam is 25 and Alexis is 10