3) 45+30х+5х²=5(9+6х+х²)=5(3+х)²

5) -2m²+4m-2=-(2m²-4m+2)=-2(m²-2m+1)=-2(m-1)²

6) 6x²+24y²+24xy=6(x²+4y²+4xy)=6(x+2y)²

7) -24m+18m²+8=2+6-24m+18m²=2*1+2(3-12m+9m²)=2(3-12m+9m²+1)=

2(4-12m+9m²)=2(2-3m)²

8) 36+24x+4x²=(6+2x)²