Do you have the rest of the question?
Answer: Ratio of new volume to original volume is 2:1.
Step-by-step explanation:
Let the radius of cylinder be 'r'
Let the height of cylinder be 'h'
Original volume of cylinder will be

If radius get doubled,
New radius be '2r'
If height get halved,
New height be will be

so, Volume of cylinder becomes

Ratio of new volume to the original volume is given by

Hence, Ratio of new volume to original volume is 2:1.
Following order of operations:
3^2 = 9
(10-2) = 8
Now you have :
9 + 8 x 5 -4
Multiplication is next:
9 + 40 -4
Now just add and subtract from left to right:
9 + 40 = 49
49-4 = 45
The answer is 45
12.8 is the answer you can multiply 3.2 to 4 or you can add 3.2 to 3.2