Question 837543



Jason is 6 years older than his sister. Their mother is years older than the sum of their ages. If their mother is 39, how old is Jason?

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1.) Get information for problem.
Let j=Jason
Let s=sister

Read first sentence- 
Jason is 6 years older than his sister.


So we can say: j=s+6


Read the second sentence-
Their mother is the sum(+) of their ages.


So from there we could say: j+s=Mothers age


Read the third sentence-
If their mother is 39...

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2nd.) Now we know how to set up the equation:
It should be-


(s+6)+s=39
2s+6=39
2s+6-6=39-6
2s=33
2s/2=33/2
s=16.5 <----------------Sisters age


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3rd.) From step 1, we know since Jason is 6 years older than his sister we are going to add. Use the value we got for his sisters age in step 2.



j=s+6
j=16.5+6
j=22.5 <---------------Jasons age


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4th.) Just to check.

Jasons age+Sisters Age=Mothers age



j+s=mothers age
(22.5)+(16.5)=39
39=39
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Jason is 22.5 years old.