Find the dimensions of the box described. The length is twice as long as the width. The height is 4 inches greater than the width. The volume is 48 cubic inches. Find the length, width, height

Respuesta :

Answer:

Width of box= 2inches

Length of box= 4inches

Height of box= 6inches.

Step-by-step explanation:

Let width of box=x inches

Length of box = twice of width=[tex]2\times x[/tex]=[tex]2x[/tex]

Height of box= 4 inches greater than width= [tex]x+4[/tex]

Volume of box= 48 cubic inches

We know that the formula of volume of cuboid= [tex] length\times breadth\times height[/tex]

Apply the formula

Volume of box= [tex]x\times 2x\times (x+4)[/tex]

Volume of cube = [tex]2x^2(x+4)[/tex]

[tex]2x^2(x+4)=48[/tex]

[tex]x^2(x+4)=24[/tex]

[tex]x^3+x^2-24[/tex]

Apply inspection method to solve the equation

Put [tex]x=0[/tex]

Then we get [tex]-24\neq0 [/tex]

Hence, x=0 is not the solution of x

Put x=1 in the equation then we get

[tex]-22\neq 0[/tex]

Hence x=1 is not the solution of equation.

Put x=2 then we get

[tex](2)^3+(4)^2-24[/tex]

8+16-24=0

Hence, x=2 is the solution of equation .

[tex] (x-2)(x^2+6x+12)[/tex]=0

Now substitute equation [tex]x^2+6x+12[/tex]=0

Sum roots =6

Product of roots=12

When sum of roots  is greater than zero and product of roots is greater than zero then value of roots of equation is imaginary.

Hence, the roots of equation [tex]x^2+6x+12=0[/tex] are imaginary.

Lenght , widht and height are dimensions of box therefore, imaginary value are not possible.

Hence,[tex] x=2 [/tex] is the only real values of root of equation .Therefore, it is possible and other two imaginary value of roots are not possible .

Widht of box=2 inches

Length of box = [tex]2\times2[/tex]=4inches

Height of box=[tex]x+4[/tex]=2+4=6 inches