SOLUTION: One dimension of a cube is increased by 1 inches to form a rectangular block.supposed that the volume of the new block is 150 cubic inches. find the length of an edge of the origin

Algebra ->  Rectangles -> SOLUTION: One dimension of a cube is increased by 1 inches to form a rectangular block.supposed that the volume of the new block is 150 cubic inches. find the length of an edge of the origin      Log On


   

Question 980480: One dimension of a cube is increased by 1 inches to form a rectangular block.supposed that the volume of the new block is 150 cubic inches. find the length of an edge of the original cube
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
x%5E3 original block volume.

x%5E2%28x%2B1%29=150 new block volume.

x%5E3%2Bx%5E2=150

x%5E3%2Bx%5E2-150=0
Look for rational roots with Rational Roots Theorem; three of them at most.
Quick but good guess is that 5 may be a root. Try checking this with synthetic division... I did not; I'm still assuming.

So imagining highlight%28highlight%28x=5%29%29 is a solution,
x%5E3=125 is the original volume.