1.(3y-8)(y+1) 2.(2y-9)(2y+9) 3.(x-5)(x+5) tlg di jawab pakai cara

1. 3y2 + 3y - 8y - 8
   = 3y2 - 5y - 8
2. 4y2 + 18y - 18y - 81
   = 4y2 - 81
3. x2 + 5x - 5x - 25
   = x2 - 25