<PRE><B>Question 1067225</B>
f-4 = 4(s-4)
f-4 = 4s-16
f = 4s-12
4s-f = 12 (1)
&lt;&gt;&lt;&gt;&lt;&gt;&lt;&gt;&lt;&gt;&lt;&gt;&lt;&gt;&lt;&gt;&lt;&gt;&lt;&gt;&lt;&gt;
f-8 = 10(s-8) 
f-8 = 10s-80 
f = 10s-72
10s-f = 72 (2)
&lt;&gt;&lt;&gt;&lt;&gt;&lt;&gt;&lt;&gt;&lt;&gt;&lt;&gt;&lt;&gt;&lt;&gt;&lt;&gt;&lt;&gt;&lt;&gt;
multiply all terms in (1) times -1 and add to (2):
10s-f = 72
+
-4s+f = -12
------------
6s+0 = 60
6s = 60
s = 10 the son is 10. And the father is:
f-4 = 4(10-4)
f-4 = 24
f = 28 the father is 28
Check: let&#39;s try the answers on the second equation
f-8 = 10(s-8)
28-8 = 10(10-8)
20 = 10(2) and 10*2 is 20, my answer is correct.

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