Hello, there!
Matthew is 8 years older than his brother. Use b to represent how old Matthew's brother is.
This means that Matthew's brother is 8 years younger than Matthew.
We will let 'M' represent Matthew's age and 'B' represent Matthew's brother's age.
The equation to represent this situation would be:
B = M - 8
I hope I helped!
Let me know if you need anything else!
~ Zoe