3.
=5а(b+2a)
=7n(2nm-1)
=2z³(z²-2)
=ax(x-3)
=xy(y²+5xy-3x)
4
=9a²-3a-30+30=9a²-3a
=8x-(15x²+5x+3x+1)=8х-15х²-8х-1=-15х²-1
=х²-3х+5х-15-х²-х=х-15
=у²+2у+3у+6-у²+у=6у+6
5.
=9а²-6ab+b²
=25+10y+y²
=36a-48ab+16b²
=1/4y²-2xy+4x²
=a^4+6a²b³+9b^6
6/
=x²+2*2*х+2²=(х+2)²
=х²-2*5*х+5²=(х-5)²