A boy is y years old. His sister is 4 years older than him, his younger brother 2 years younger than him and his grandmother 8 times older than him. Write an expression for the ages of his sister, younger brother and grandmother.
As his sister is 4 years older than him, the expression for her age is y + 4.
As his younger brother is 2 years younger than him, his age is y − 2.
As the grandmother is 8 times older than him, her age can be expressed as 8y.