Currently, Sam's coach is three times older than Sam. When Sam started soccer 5 years ago, his coach was five times his age. How old is Sam now?

Question

anonymous · Answer

Sam is ten. His coach is 3x older than him, so his coach is 30. Five years ago, Sam was 5 and his coach was 25. 25/5=5

gabylovesyou · Answer

so the answer is 10

anonymous · Answer

@Snapbacklive  how did you know sam was 10?

anonymous · Answer

Sam's coach is three times older than Sam' tells you y = 3x.
 
Also, 5 years ago, Sam's age was x-5 and the coach's age was y-5. Now the coach's age was 5 times Sam's age, so
 
y-5 = 5(x-5), and expanding out the right hand side
 
y-5 = 5x - 25
 
Substituting y = 3x gives
 
3x - 5 = 5x - 25
 
Adding 25 to both sides
 
3x + 20 = 5x
 
Subtracting 3x from both sides
 
2x = 20
 
Dividing through by 2, x = 10 and Sam is ten years old.

anonymous · Answer

@Gabylovesyou 
coach: 3x-5 = 5y....(i)
sam:    x-5 = y....(ii)
substitute in (i)
3x-5 = 5(x-5)
3x-5 = 5x-25
3x-5x  = -25+5
-2x = -20 
x = 10

anonymous · Answer

yup

gabylovesyou · Answer

thank u!

anonymous · Answer

ur welcome