Question 311489
<font face="Garamond" size="+2">


Let *[tex \Large x] represent the age of the father.  Let *[tex \Large y] represent the age of the son.  Then


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ x\ +\ y\ =\ 100]


and


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ x\ -\ 30\ =\ 3(y\ -\ 30)]


Solve the first equation for y:


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ y\ =\ 100\ -\ x]


Substitute:


*[tex \LARGE \ \ \ \ \ \ \ \ \ \ x\ -\ 30\ =\ 3\left((100\,-\,x)\ -\ 30\right)]


Just solve for *[tex \Large x].  The other value follows directly.


John
*[tex \LARGE e^{i\pi} + 1 = 0]
</font>