tolong yang jago matematika noner 1 sampai 5

semoga dapat membantu

1.
[tex] {2x}^{2} + 3xy - {y}^{2} + {x}^{2} + xy + {2y}^{2} \\ sederhanain \: dulu \\ {3x}^{2} + 4xy + {y}^{2}[/tex]
Jumlah suku = 3 (A)

2. 3a + (-5b) - a - 4b
3a - a - 5b - 4b
2a - 9b (C)

3.
[tex]2 - {3x}^{2} - ( {x}^{2} - 2x) \\ 2 - {3x}^{2} - {x}^{2} + 2x \\ - {4x}^{2} + 2x + 2 [/tex]
A

4. 3xy - 12y
3y(x - 4)
B.

5.
[tex]81 {a}^{4} - 625 {b}^{4} \\ (9 {a}^{2} + 25 {b}^{2} )(9 {a}^{2} - 25 {b}^{2} ) \\ (9 {a}^{2} + 25 {b}^{2} )(3a + 5b)(3a - 5b)[/tex]
A.