Respuesta :
Answer:
Sam is 7 and 1/2 years old.
Step-by-step explanation:
Let Sam be x years old. Then we have the equation:
2x + 6 = 21
2x = 21-6 = 15
x = 7.5.
7½yrs
Step-by-step explanation:
Sam = x
Oliver = 6 + 2x
Sam = (21-6) ÷2
Sam=15÷2
Sam=7½yrs