Answer:
Sipho is 10 years old.
Litha is 19 years old.
Explanation:
We will use variables as their age.
x for Sipho
y for Litha
Here's what we know:


Now we just need to isolate a variable in order to begin a system of equation.

Now that we have y in terms of x we just need to plug in

Now that we know x we now must find y.

We are done! Sipho is 10 years old and Litha is 19 years old.