Answer: hello your question is incomplete attached below is the complete question
answer :
a)
( option D )
b) A = 1/2 (6)(3) ( option B )
c) Area of shaded region = 9
Step-by-step explanation:
<u>a) Using integration with respect to x </u>
Area =
( note a = 10 )
= y^2/2 - 4y |⁷₄ + 10y - y^2/2 |¹⁰₇
= 33/2 - 12 + 30 - 51/2 = 9
hence the best integral from the options attached is option D

= [ 10x - x^2 /2 - x^2/2 - 9x ] ³₀
= 30 - 9/2 - 9/2 - 12 = 9
<u>b) Using Geometry </u>
Area = 1/2 * base * height
= 1/2 * 6 * 3
= 9
Answer: 
Step-by-step explanation:
Given
Radius of cylinder 
The height of the cylinder is 
The surface area of a cylinder is 
If only the outer is considered then, the area required is

-.x+7
-x+7=0
-x=-7
x=7...
Not too sure because of the way you wrote the question but this is the interpretation i gave it.