Объяснение:
y(y-5)(y+5)-(y²-2y+4) =
= y(y²-25)-y²+2y-4 =
= y³-25y-y²+2y-4 =
= y³-y²-23y-4
у×(у-5)×(у+5)-(у²-2у+4)= у²-5у×(у+5)-(у²-2у+4)=
=у³-5у²+5у-25у-(у²-2у+4)= у³-5у²+5у-25у-у²+2у-4=у³-6у²-18у-4
