[tex]3y {}^{2} - 6yz - 7 + 4 {y}^{2} - \\ \: 4yz + 2 - y {}^{2} z \\ [/tex]
[tex]3 {y}^{2} + 4y {}^{2} - 6yz + 4yz \\ - 7 + 2 - {y}^{2} z[/tex]
[tex]7 {y}^{2} - 10yz - {y}^{2} z - 5[/tex]
The answer is the 2nd one from the bottom.
7y2 - y2z - 10yz -5
