Answer:
Sophia is 26 years old
Avery is 6
Explanation:
Let the age of Sophia be s
Let the age of Avery be a
Setting up our system of equations
s=5a-4
s+4=3(a+4)
Simplifying gets us
s+4=3a+12
s=3a+8
Subsisting gets us
5a-4=3a+8
2a=12
a=6
Solving for s gets us s=30-4=26