Question

If the volume of a cuboid is 3x² − 27, then its possible dimensions are

विकल्प

• 3, x², − 27x

• 3, x − 3, x + 3

• 3, x², 27x

• 3, 3, 3

Answer 1

We have to find the possible dimension of cuboid 

Given: volume of cuboid `3x^2 - 27`

 `3x^2 -27 = 3x^2 - 3xx 3 xx 3`

 ` = 3x^2 - 3 xx 3 xx 3`

Take 3 as common factor

 `3x^2 - 27 = 3(x^2 - 3^2)`

Using identity  `x^2 -y^2 = (x+y)(x-y)`

We get,

 `3x^2 - 27 =3(3x+3) (x-3)`

Here the dimension of cuboid is 3,3, x + 3, x - 3