Номер 403:
1)2x(x^2+5x+3)=2x^3+10x^2+6x
2)3y(y^3-3y-4)=3y^4-9y^2-12y
3)-2xy(x^2+2xy-y^2)=-2x^3y-4x^2y^2+2x^3
4)-5mn(m^3+3m^2n-n^3)=-5m^4n-15m^3n^2+5mn^4
номер 406:
1)3x(x-5)-5x(x+3)=3x^2-15x-5x^2-15x=-2x^2-30x
2)2y(x-y)+y(3y-2x)=2xy-2y^2+3y^2-2xy=y^2
3)2a(a-b)+2b(a+b)=2a^2-2ab+2ab+b^2=2a^2+b^2
4)3p(8c+1)-8c(3p-5)=24pc+3p-24pc+40c=3p+40c