Answer with Step-by-step explanation:
Let Carlos sister's age be y.
Carlos is 13.
Carlos is five years older than twice his sister's age.
⇒ 13=2y+5
or 2y+5=13
Equation which correctly identifies his sister's age is:
2y+5=13
⇒ 2y=13-5
⇒ 2y=8
Dividing both sides by 2 gives
y=4
Hence, Carlos sister's age is:
4