bang kak. tolong jawab ya beserta jalan nya, besok di kumpul. makasihh !!

1. (x+10) (x+3) = ( x^2 + 3x + 10x +30) = x^2+13x+30
2. (x-2) (x+7) = ( x^2 + 7x - 2x - 14) = x^2+5x-14
3. (3x+4x) (3x-7) = ( 9x^2 -21x +12x^2 -28x) = 21x^2-49x
4. (2x-1) (x+1) = ( 2x^2 + 2x -x -1) = 2x^2 + x -1

^ = pangkat