1) А) (y-8)(y+5)=y^2 +5y-8y-40= y^2 -3y -40
Б) (5p+c)(2p+4c)=10p^2 +20pc +2pc + 4c^2=10p^2+22pc +4c^2
В) (4a-2)(3a-2)=12a^2-8a-6a+4= 12a^2 -14a+4
Г)(x-2)(x^2+5x-4)=x^3+5x^2-4x-2x^2-10x+8=x^3+3x^2-14x
2)А) p(c-p)+2c(c-p)=(p+2c)(c-p)
Б) 4x-4y+ax-ax=4(x-y)
3)0,5y(4-2y^2)(y^2+3)=0,5y(4y^2 +12 -2y^4 -6y^2)= 0,5y(-2y^4 -2y^2 +12)=-y^5-y^3+6y