Question 1117671
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Amy   + Chau + Juan = 90


A     + C    + J    = 90

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(C+5) + C + 3*(C+5) = 90


3C + 5 + 15  = 90


5C + 20 = 90  ====>  5C = 90 - 20 = 70  ====>  C = {{{70/5}}} = 14.


<U>Answer</U>.  Chau has  14;   Amy  has 14+5 = 19;  Juan has  3*19 = 57.


<U>Check</U>    14 + 19 + 57 = 90.   ! Correct ! 
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Solved.