Given:
Find-:
Dimensions of the cardboard
Explanation-:
The volume of a quadrangular prism is:
![V=l* w* h](https://img.qammunity.org/2023/formulas/mathematics/college/6r1v4jyudv1wid1xri6o6h85nmm0m84ukq.png)
The length is 12 more than the width is:
![\begin{gathered} \text{ Width =}y \\ \\ \text{ Length =}y+12 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/high-school/bv9biiw2ilf2mmevxch0hh06c9m608gqmj.png)
Hight is 6.
So the Area is:
![\begin{gathered} V=l* w* h \\ \\ V=(y+12)*(y)*(6) \\ \\ V=6y(y+12) \\ \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/high-school/7tbkod5uzsozkww5s6ma0ttvd4ot7dair7.png)
Given that volume is 2958 so,
![\begin{gathered} 6y(y+12)=2958 \\ \\ y(y+12)=(2958)/(6) \\ \\ y^2+12y=493 \\ \\ y^2+12y-493=0 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/high-school/pc6ezip3s0yjdyjwpm25wrh5igln6dz1q1.png)
Solve the quadratic equation is:
![\begin{gathered} ax^2+bx+c=0 \\ \\ x=(-b\pm√(b^2-4ac))/(2a) \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/high-school/yns9mje4ec6d873f1mz76sc04vk39kgqv5.png)
![\begin{gathered} y^2+12y-493=0 \\ \\ y=(-12\pm√(12^2-4(1)(-493)))/(2) \\ \\ y=(-12\pm√(2116))/(2) \\ \\ y=(-12\pm46)/(2) \\ \\ y=-6\pm23 \\ \\ y=-6-23;y=-6+23 \\ \\ y=-29,y=17 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/high-school/4ep4nkctj7la8nn7d6frdum90r8rbpl5j7.png)
A negative value is not considered because sides are always positive so y is 17.
So the width is 17 and length is:
![\begin{gathered} \text{ Length}=y+12 \\ \\ \text{ Length =}17+12 \\ \\ \text{ Length =}29 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/high-school/lpebrb0dt9t8l4ch0umbprgvx5t42ekhxi.png)
So dimensions are 29 in. by 17 in.