katie is 4 years younger than sylvia. let k represent katie's age and let s represent slyvia's age.
To solve this problem, we need to understand the relationship between Katie's age (k) and Sylvia's age (s). According to the information given, Katie is 4 years younger than Sylvia. This can be expressed as the equation:
k = s - 4
In this equation, k represents Katie's age and s represents Sylvia's age.
With this equation, we can determine Katie's age if we know Sylvia's age, or vice versa.