Answer:
See Below
Step-by-step explanation:
The surface area of cylinder is given by the formula:

Where
r is radius ( diameter is 4, so radius is 4/2 = 2)
h is height ( h = 9)
Lets find original surface are:

<u>Halving diameter:</u>
diameter would be 4/2 = 2, so radius would be 2/2 = 1
So, SA would be:

<u>Halving height:</u>
Height is 9, halving would make it 9/2 = 4.5
Now, calculating new SA:

Original SA is
,
Halving diameter makes it 
Halving height makes it 
So, halving diameter does not have same effect as halving height.
Answer:
decreased 11.7647 percent
3(2c+d)-4(c-d)+d^2
c=1 , d=3
Use the substitution method
3(2*1+3)-4(1-3)+3^2
Multiply the brackets
3(2+3)-4+12+9
6+9-4+12+9
15-4+12+9
11+21
=32
Answer: 32
I'm not sure but I think it is
4.48×10 10 <---this to is an exponent