To find the surface area of a cylinder, use the formula SA = 2(pi)(radius^2) + 2(pi)(radius)(height).
So now, plug in what you know.
SA = 2(3.14)(5^2) + 2(3.14)(5)(9)
SA = (6.28)(25) + (6.28)(45)
SA = 157 + 282.6
SA = 439.6 square cm
439.6 square cm is your surface area
In order to write

as a percentage, we must first convert the fraction into a decimal. We can do that simply by dividing.
35 / 20 = 1.75
In order to convert a fraction to a decimal, we must multiply it by 100
1.75 * 100 = 175%

as a percentage is 175%.
Hope that helped =)
As points, x-intercepts take the form

, so to find the intercepts we can set

and solve for

.

From the first equation alone, we already know that

is a solution, which means one intercept is

.
The second equation gives

so that the second intercept occurs at

.
So if

and

, we have

, giving C as the answer.
When shopping, you use a math calculation to see if the price is on sale and how much it costs, and when adding up all the things you bought, by mostly rounding.
Hope helps!-Aparri