1) (x²-196)
2) (6a-7)(7+6a)
3) a³+8
4) a²-10a+25

1 (х2-196)=(х-14)(х+14)2 (6а-7)(7+6а)=42а+36а2-49-42а=36а2-493 а3+8=(а+8)(а2-2а+4)4 а2-10а+25=1а-19а+25=(1-10)а+25=-9а+25