cara no 1-6 bagaimana ya

1. A
[tex]5y ^{2} - 7y + 3y ^{2} - 4 + 5y \\ = 8 {y}^{2} - 2y - 4[/tex]
2. B
4x²-3x+6-x²+7x-3
=3x²+4x+3

3.