If the volume of a box is 2x3 + 4x2 − 30xwhich of the dimensions are possible with the given x-value?

A. x = 1; dimensions: 8 by 9 by 1
B. x = 1; dimensions: 2 by 5 by 3
C. x = 4; dimensions: 2 by 5 by 3
D. x = 4; dimensions: 8 by 9 by 1

Respuesta :

The possible value of x = 4, dimensions 8 by 9 by 1 (option D), if the volume of a box is [tex]2 x^{3} + 4 x^{2} -30x[/tex].

Step-by-step explanation:

The given is,

                        [tex]2 x^{3} + 4 x^{2} -30x[/tex]................................(1)

Step:1

    Check for option A,

             x = 1, dimensions 8 by 9 by 1  

            From the equation (1),

                      Volume = [tex]2 (1^{3}) + 4 (1^{2} )-30(1)[/tex]

                                    [tex]=2+4-30[/tex] = -24...................(2)

            From the dimensions,

                      Volume = ( 8 × 9 × 1 )

                                     = 72............................................(3)

            From equation (2) and (3)

                                -24 ≠ 72

            So, X=1; dimensions 8 by 9 by 1 is not possible.

   Check for option B,

             x = 1, dimensions 2 by 5 by 3

            From the equation (1),

                      Volume = [tex]2 (1^{3}) + 4 (1^{2} )-30(1)[/tex]

                                    [tex]=2+4-30[/tex] = -24...................(4)

            From the dimensions,

                      Volume = ( 2 × 5 × 3 )

                                     = 30.........................................(5)

            From equation (4) and (5)

                                -24 ≠ 30

            So, X=1; dimensions 2 by 5 by 3 is not possible.

   Check for option C,

            x = 4, dimensions 2 by 5 by 3

            From the equation (1),

                      Volume = [tex]2 (4^{3}) + 4 (4^{2} )-30(4)[/tex]

                                    [tex]=2(64)+4(16)-30(4)[/tex]

                                    [tex]= 128+64-120[/tex]

                                    = 72.............................................(6)

            From the dimensions,

                      Volume = ( 2 × 5 × 3 )

                                     = 30............................................(7)

            From equation (6) and (7)

                               72 ≠ 30

            So, X=4; dimensions 2 by 5 by 3 is not possible.

    Check for option C,

            x = 4, dimensions 8 by 9 by 1

            From the equation (1),

                      Volume = [tex]2 (4^{3}) + 4 (4^{2} )-30(4)[/tex]

                                    [tex]=2(64)+4(16)-30(4)[/tex]

                                    [tex]= 128+64-120[/tex]

                                    = 72............................................(8)

            From the dimensions,

                      Volume = ( 8 × 9 × 1 )

                                    = 72............................................(9)

            From equation (8) and (9)

                               72 = 72

            So, X=4; dimensions 8 by 9 by 3 is possible.

Result:

           The possible value of x = 4, dimensions 8 by 9 by 1 (option D), if the volume of a box is [tex]2 x^{3} + 4 x^{2} -30x[/tex].