Evaluate the following integral by making an appropriate change of variable.
I don't know how to use the math tags, so I attached it.
I set u = x+y and v=y-2x. Then I note that the sides are x=0, y=0, and x=y. What next?
In an e-mail I got you said you had difficulty finding x and y in terms of u and v but it seems you figured it out
In case you haven't there are 2 ways
1. Using matrices --see attachment
2.Brute force and ignorance
v = -2x+y
subtract the 2 eqns --this eliminates y solve for x
use the result in either eqn to find y