Question 1068207
Peter,John,Molly and Stan are 100years old combined.
Stan is 4 years younger than Peter. Johns age is 1 1/2 times Mollys age.
2 years ago was Stans age 6 times Mollys age. 
How old are Peter, John,Molly and Stab separate? 
---------------------------
p + j + m + s = 100
s = p-4
j = (3/2)m
s-2 = 6(m-2)
-------------------
p + j + m + s = 100
p + 0 + 0 - s =   4
0 + 2j-3m + 0 =   0
0 + 0 +6m - s =  10
----------------------
Use any method you know to solve this system to get:
p = 42
j = 12
m = 8
s = 38
----
I used my TI-84+ Matrix function to get the solution.
Cheers,
Stan H.
-------------