Exercises on Partial Derivatives

[MathematicalPhysicist]

here there are Exercises on Partial Derivatives: http://www.ualberta.ca/dept/math/gauss/fcm/calculus/multvrbl/basic/partl_drvtvs_exrcss/partl_dervtv_exrcss.htm
can comeone please solve the first two problems (for some reason i cant read the answers).
my answers:
1. 3(3xy-4y^2)^2(3x-8y)
2. y/(x+y)^2

thanks in advance.

[Integral]

You are correct.

[futz]

Hooray for the University of Alberta! [6)]