The length of each side of a cube is 14𝑥 + 8 𝑓𝑒𝑒𝑡. Write a polynomial in standard form to represent the surface area of the cube.

The correct answer is: 384 feet2

The length of each side of a cube is 14x + 8 feet.
Surface area of the cube = 6(14x + 8)²

 (14x + 8)² = (14x + 8)(14x + 8)

= 14x(14x + 8) + 8(14x + 8)

= 14x(14x) + 14x(8) + 8(14x) + 8(8)

= 196 x² + 112x + 112x + 64

= 196 x² + 224x + 64
Surface area of the cube = 6(14x + 8)²

= 6(196 x² + 224x + 64)

= 1176 x² + 1344x + 384 feet²
Final Answer:
Hence, the polynomial which represents the surface area of the cube of 14x + 8 feet side is 1176 x² + 1344x + 384 feet².
 

This question can be easily solved by using the formula
(a + b)2 = a2 + 2ab + b2