Final answer:
The expression for Mike's age in terms of x is 3x + 4.
Step-by-step explanation:
To find Mike's age, we need to understand the given information:
- Kate is x years old
- Lethna is 3 times as old as Kate
- Mike is 4 years older than Lethna
Since Lethna is 3 times as old as Kate, her age is 3x. And since Mike is 4 years older than Lethna, his age would be 3x + 4.
Therefore, the expression for Mike's age in terms of x is 3x + 4.