SOLUTION: A rectangular storage bin is to be made from a rectangular piece of sheet metal 12 cm by 10 cm, by cutting out equal corners of side x and bending up the sides. Find x if the sto

Algebra ->  Polynomials-and-rational-expressions -> SOLUTION: A rectangular storage bin is to be made from a rectangular piece of sheet metal 12 cm by 10 cm, by cutting out equal corners of side x and bending up the sides. Find x if the sto      Log On


   

Question 331450: A rectangular storage bin is to be made from a rectangular piece of sheet metal
12 cm by 10 cm, by cutting out equal corners of side x and bending up the
sides. Find x if the storage bin is to hold 90cm³(volume).
I got up to here and I am stuck
4x³ - 44x²+ 120x + 90 = 0
However, my question is worth 8marks and I dont think i am allowed to use a graphic calculator to work it out. How do i answer this question properly?
Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
4x^3 - 44x^2 + 120x = 90

2x^3 - 22x^2 + 60x - 45 = 0

test for roots using [(factors of -45) / (factors of 2)]


doesn't seem to be an integer value (maybe not rational) , so Guess-Divide-Average might be the way to solution