Question 99028
Ok
we are given George's age is equal to x.
so now we have to express the other peoples ages in terms of x.
lets start with Sam.
Given: Sam is {{{1/2}}} the age of George
so Sam's age = {{{x/2}}}
Given: George is 4 years older than Jan.
so Jan's age = {{{x - 4}}}
Given: Jim is 4 years older than Sam
so Jim's age = {{{(x/2)+4}}}
Now we have expressions for everyone's age in terms of x and we are given the sum of everyone's age to be 72 so we can write and equation to solve for x.

{{{x+(x/2)+(x-4)+((x/2)+4)=72}}}
{{{x+x/2+x-4+x/2+4=72}}}
{{{2x+x/2+x/2=72}}}
{{{2x+2x/2=72}}}
{{{2x+x=72}}}
{{{3x=72}}}
{{{x=24}}}
So George is 24 years old. To find the age of the other people just plug in 24 for the x in each person age expression.