Cara's brother is 4 years old, she is 8 when will she be triple the age of him?

Let x be the number of years for the Cara to be triple of her brother's age.

Brother = 4 years old

Cara = 8 years old

8 + x = 3 (4 + x)

8 + x = 12 + 3x

3x - x = - 4

2x = - 4

x = - 2

She was triple his age 2 years ago but she will never to triple his age in the future.