Selesaikan operasi perkalian aljabar! a.(×+1) (×+2) b.(3×+y) (3×-y) c.(2a-3) (a-4)

1. x² + 2x + x + 2
= x² + 3x + 2
2. 9x² - 3xy + 3xy - y²
= 9x² - y²
3. 2a² - 8a - 3a + 12
= 2a² - 11a + 12

a.
(x+1)(x+2)
= x² + 2x + x + 2
= x² + 3x + 2

b.
(3x+y)(3x-y)
= 9x² - 3xy + 3xy - y²
= 9x² - y²

c.
(2a-3)(a-4)
= 2a² - 8a - 3a + 12
= 2a² - 11a + 12