Substitute $\displaystyle s = x - 5$ in the formula for the surface area of a cube:

$\displaystyle A = 6s^{2}$

$\displaystyle A = 6 \left ( x - 5\right )^{2}$

$\displaystyle A = 6 \left ( x^{2} - 2 \cdot 5 \cdot x + 5^{2}\right )$

$\displaystyle A = 6 \left ( x^{2} - 10x +25\right )$

$\displaystyle A = 6 x^{2} - 60x +150$

To find the surface area of a cube, use the formula $\displaystyle 6s^{2}$, where $\displaystyle s$ represents the length of the side.  Since the side of the cube measures $\displaystyle 4$, we can substitute $\displaystyle 4$ in for $\displaystyle s$.

$\displaystyle 6(4)^{2}=96\: cm^{2}$

The surface area of a non-cubic prism can be determined using the equation:

$\displaystyle SA=2lw+2wh+2lh$

$\displaystyle SA=2(7)(6)+2(6)(2)+2(7)(2)=84+24+28=136$

To find the surface area of the rectangular box we just need to add up the areas of all six sides. We know that two of the sides are 36 square centimeters, that means we need to find the areas of the four mising sides. To find the area of the missing sides we can just multiply the side of one of the squares (6 cm) by the width of the box:

$\displaystyle 6 \times 10 = 60 \; cm^2$

But remember we have four of these rectangular sides:

$\displaystyle 4 \times 60 = 240 \; cm^2$

Now we just add the two square sides and four rectangular sides to find the total surface area of the jewelry box:

$\displaystyle 36 \; cm^2 + 36 \; cm^2 + 240 \; cm^2 = 312 \; cm^2$

That is the total surface area!

The surface area of a rectangular prism is given by

$\displaystyle \textup {SA=2lw+2lh+2wh}$ where $\displaystyle l$ is the length, $\displaystyle w$ is the width, and $\displaystyle h$ is the height.

Let $\displaystyle \textup l=5\textup { in}$, $\displaystyle \textup {w}=6\textup{ in}$, and $\displaystyle \textup {h}=12\textup { in}$

So the equation to solve becomes $\displaystyle \textup SA=2\cdot 5\cdot 6+2\cdot 5\cdot 12+2\cdot 6\cdot 12$ or $\displaystyle 324\textup{ in}^{2}$

However the question asks for an answer in square feet.  Knowing that $\displaystyle 144\textup { in}^{2}=1\textup { ft}^{2}$ we can convert square inches to square feet.  It will take $\displaystyle 2.25\textup{ ft}^{2}$ of paper to wrap the present.

In order to solve this problem, we need to recall the area formula for a circle:

$\displaystyle A=r^2\pi$

Now that we have the correct formula, we can substitute in our known values and solve: 

$\displaystyle A=12^2\pi$

$\displaystyle A=144\pi\textup{ in}^2$

In order to solve this problem, we need to recall the area formula for a circle:

$\displaystyle A=r^2\pi$

Now that we have the correct formula, we can substitute in our known values and solve: 

$\displaystyle A=19^2\pi$

$\displaystyle A=361\pi\textup{ in}^2$

In order to solve this problem, we need to recall the area formula for a rectangle:

$\displaystyle A=l\times w$

Now that we have the correct formula, we can substitute in our known values and solve: 

$\displaystyle A=12\times10$

$\displaystyle A=120\textup{ in}^2$

In order to solve this problem, we need to recall the area formula for a rectangle:

$\displaystyle A=l\times w$

Now that we have the correct formula, we can substitute in our known values and solve: 

$\displaystyle A=11\times4$

$\displaystyle A=44\textup{ in}^2$

The perimeter of a rectangle is 2L + 2W, or 2 times the length plus 2 times the width.  Here you're given that side BC is 4, which means that the opposite side, AD, is also 4.  So since that is two widths, you now have:

8 + 2L = 48

So 2L = 40

That means that the length is 20.

Since the area is LW, you can calculate the area as 20 * 4 = 80.