SOLUTION: a box has a square base, with xcm sides, and the height 2cm more then the length, the surface area of the box=120cm^2, find x..

Algebra ->  Surface-area -> SOLUTION: a box has a square base, with xcm sides, and the height 2cm more then the length, the surface area of the box=120cm^2, find x..      Log On


   

Question 429219: a box has a square base, with xcm sides, and the height 2cm more then the length, the surface area of the box=120cm^2, find x..
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!


Hi

a box has a square base, with xcm sides and (x+2)height

Surface area = x^2 + x^2 + 4[x(x+2)]

  2x^2 +4x^2 + 8x = 120 cm^2

     6x^2 + 8x - 120 = 0

     3x^2 + 4x - 60 = 0

x+=+%28-4+%2B-+sqrt%28+736+%29%29%2F%286%29+

  x = 3.8549cm   |tossing out negative solution for length