f(x,y)=x10-3xy2then fz=
A. 10 x9 - 3y2
B. 20 x9 - 3y2
C. 2y2
D. 10x10 + xy2
which option is correct please
![fxyx103xy2then fz A 10 x9 3y2 B 20 x9 3y2 C 2y2 D 10x10 xy2 which option is correct please class=](https://us-static.z-dn.net/files/dba/eebbc7125ae21adb318dc27168d772d8.png)