Question 1185055
.
Five years from now, Jabin's grandmother will be 3 times as old as Jabin. 
The sum of the squares of their ages in 5 years is 8410. what is Jabin's present age?
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            This problem has a simple and elegant solution.  All you need is to look 

            at the problem from the right point of view . . . 



<pre>
Let x be the Jabin's age in 5 years from now.

Then the grandmother's age in 5 years from now will be 3x, according to the condition.


Now we write equation for x as we read the problem


    x^2 + (3x)^2 = 8410.


Simplify and find x


    x^2 + 9x^2 = 8410

       10x^2 = 8410

         x^2 = 841

         x   = {{{sqrt(841)}}} = 29  is the Jabin's age in 5 years from now.


<U>ANSWER</U>.  This year, Jabin is  29-5 = 24 years old.
</pre>

Solved.


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There is a bunch of lessons on age word problems 

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=http://www.algebra.com/algebra/homework/word/age/Age-problems-and-their-solutions.lesson>Age problems and their solutions</A>

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=https://www.algebra.com/algebra/homework/word/age/02-HOW-TO-algebreze-and-solve-age-problems.lesson>HOW TO algebreze and to solve age problems?</A> 

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=http://www.algebra.com/algebra/homework/word/age/Fresh-formulation-of-a-traditional-age-problem.lesson>A fresh formulation of a traditional age problem</A>

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=http://www.algebra.com/algebra/homework/word/age/Really-intricate-age-word-problem.lesson>Really intricate age word problems</A>

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=https://www.algebra.com/algebra/homework/word/age/Selected-age-word-problems-from-the-archive.lesson>Selected age word problems from the archive</A>

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=https://www.algebra.com/algebra/homework/word/age/Age-problems-for-mental-solution.lesson>Age problems for mental solution</A> 

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=https://www.algebra.com/algebra/homework/word/age/Age-problem-for-3-participants.lesson>Age problem for three participants</A> 

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=https://www.algebra.com/algebra/homework/word/age/Miscellaneous-age-problem.lesson>Miscellaneous age problems</A> 

in this site.


Read them and become an expert in solving age problems.


Also, &nbsp;you have this free of charge online textbook in ALGEBRA-I in this site

&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson>ALGEBRA-I - YOUR ONLINE TEXTBOOK</A>.


The referred lessons are the part of this online textbook under the topic "<U>Age word problems</U>".



Save the link to this online textbook together with its description


Free of charge online textbook in ALGEBRA-I
https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson


to your archive and use it when it is needed.