Question 333422
first, your answers, of Jean=32 and Michael 16, have you tested them to see if they are correct?   The sum of their ages 3 years ago was 45 years
Let see, 3 years ago Jean=32-3=29, Michael=16-3=13 so their sum is 42, so your answers are incorrect!
---
Begin by letting J=Jean's age and M=Michaels age, you have two unknowns J and M
and you need as many equations as unknowns.
--
Jean is twice as old as Michael
J=2*M  [ this is your first equation ]
---
The sum of their ages 3 years ago was 45 years
J-3 is jean's age 3 years ago
M-3 is Michaels age 3 years ago,  so....
(J-3) + (M-3)=45   [ this is your second equation]
---
simplify the second equation
(J-3) + (M-3)=45 
J+M-6=45
J+M=51

---
So now you have two equations and 2 unknowns
There are many ways to solve this, substittution, elimination, matrices, graphing, guessing, cramer method, etc......
---
Try subtitution since the first equation is already set to one of the variables
J =2*M
substitute this into the second equation
J+M=51
(2*M)+M=51
3*M=51
M=51/3=17
---
So if M=17 and J=2*M then J=2*(17) =34
====
Check your answers

go back to the original equations
J=2M  and (J-3) + (M-3)=45 to see if M=17 and J=34 are valid