perkalian bentuk aljabar 1. –9x (5-4x) 2. (5x-3y) (2x-7y) 3. (3x-8) (9x-2) please jawab yaa yg bener

1. -45x+36x²
2. 10x²-35xy-6xy+21y²
10x² - 41xy + 21y²
3. 27x²-6x-72x+16
27x² - 78x + 16

1. -9x(5-4x) = -45x + 36x* ( tanda * arti nya pangkat2 ya)
2. (5x-3y) (2x-7y) = -10x* - 35xy - 6xy + 21y*
= -10x* - 41xy + 21y*
3. (3x-8)(9x-2) = 27x* - 6x-72x+16
= 27x*-78x+16