Question

Currently, Sam's coach is twice as old as Sam. When Sam started soccer 10 years ago, his coach was four times his age. How old is Sam now?

Answer 1

2s = c
4(s-10) = c-10
//set up equations

4s - 40 = c -10
//simplify equations
4s - 40 + 10 = c
//get c by itself

4s - 30 = c

//substitute

2s = 4s - 30
//simplify
30 = 4s - 2s
30 = 2s
s = 15


Same is 15




//check

sam is 15 coach is 30
10 years ago

sam is 5 coach is 20