SOLUTION: d is 2 years younger than j. the difference between the squares of their ages is 28. how old is each

Algebra ->  Customizable Word Problem Solvers  -> Age -> SOLUTION: d is 2 years younger than j. the difference between the squares of their ages is 28. how old is each      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


   



Question 1112913: d is 2 years younger than j. the difference between the squares of their ages is 28. how old is each
Answer by ikleyn(52776) About Me  (Show Source):
You can put this solution on YOUR website!
.
D is 2 years younger than J. The difference between the squares of their ages is 28. how old is each
~~~~~~~~~~~~~~~~~~~~~

See what is  RIGHT  WAY  solving such problems.

You are given these two equations

J - D = 2           (1)
J%5E2 - D%5E2 = 28       (2)


From (2), you have

(J-D)*(J+D) = 28    (2')


In (2') replace (J-D) by 2, since it is given.  You have

2*(J+D) = 28,    which implies

J + D = 14.         (3)


Now you have these two equations

J - D = 2           which is the same as (1),   and

J + D = 14          which is (3).


Now add these equations . Yuo will get

2J = 2 + 14 = 16,    which implies   J = 16%2F2 = 8.


Then   D = 8-2 = 6.


Answer.  J is 8.  D is 6

Solved.