Answer:
Michael is 38 and Sara is 29
Step-by-step explanation:
Because it says the sum of their age is 47 you do 47-9=38 so that would be Michael's age and than because Sara is 9 years younger than him and then you would do 38-9=29
Substitution or elimination
Just keep putting 1 and 2 for all and then add them up and that would get you your answer