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

Hello,

Let's x the side of the cube

Volume of the cube=x^3

Volume of the rectangular block : (x+1) x²=150

So x^3+x^2-150=0

==>x^3-5x^2+6x^2-30x+30x-150=0

==>x^2 (x-5) + 6x (x-5) + 30 (x-5) = 0

==> (x-5) (x^2+6x+30) = 0

The trinome has no real roots.

==>x=5 (in)

Proof: (5+1) * 5*5=25*6=150