<PRE><B>Question 1062653</B>
let a = smallest side.
let b = medium side
let c = largest side.


a + b + c = 31


c = 3a
b = c - 4 = 3a - 4


a+ b + c = 31 becomes:


a + (3a - 4) + 3a = 31


simplify and combine like terms to get:


7a - 4 = 31


add 4 to both sides to get:


7a = 35


solve for a to get a = 5


you get:


a = 5
c = 15
b = 11


a + b + c = 31


solution is:


largest side is 15 cm.


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