(2-x)(2+x)(x-1)+x²(x-1)= если х=1.8
(4+2x-2x-x²)(x-1)+x³-x²=
(4-x²)(x-1)+x³-x²)=
4x-4-x³+x²+x³-x²=
4x-4=
4*1.8-4=
7.2-4=3.2
(2+х)(3+х)(3-х)+х²(х+2)= если х=1.8
(2+x)*(9-3x+3x-x²)+x³+2x²=
(2+x)(9-x²)+x³+2x²=
18-2x²+9x-x³+x³+2x²=
18+9x=
18+9*1.8=
18+16.2=34.2