Answer: 99
Explanation: 9+9 = 18
and when you switch the order of the digits, it is still 99.
Hope that helps ;)
The Jacobian for this transformation is

with determinant
, hence the area element becomes

Then the integral becomes

where
is the unit circle,

so that

Now you could evaluate the integral as-is, but it's really much easier to do if we convert to polar coordinates.

Then

4/3 because I typed in on my calculator
Answer:
D
Step-by-step explanation:
If the lines are parallel, the slope of both of them are going to be the same. So if one line is 3, the other one will be too.
Answer:
3
Step-by-step explanation:
x = 1
y = 1
6+4-7 = 3