Question 841567
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Hi,
x +3 +   3x-8 + x+5 +  x^2-3x = 120cm
   x^2 + 2x   + 0 = 120cm
   x^2 + 2x - 120 = 0
 (x+12)(x-10) = 0, x = 10  (throwing out negative solution for x
Sides are: 13cm , 22cm, 15cm, 70cm 
CHECKING our answer***
13cm + 22cm + 15cm + 70cm  = 120cm
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