Question

Помогите срочно даю все балы которые есть. И 5 звëзд

Answer 1

$1)\ \ 2a^2+3a^2c^2-4abc\\\\2)\ \ 5-2b-8a^3c^2-9a^3b^4\ \ \ \to \ \ \ n=7\\\\3)\ \ 4a^2b-6a^2c-4a^2b+4a^2c+7c=-2a^2c+7c\\\\4)\ \ (0,7x^2+1,2x^3-4x^4)+(0,8x^4-1,2x^2)=\\\\=(-4x^4+0,8x^4)+1,2x^3+(0,7x^2-1,2x^2)=-3,2x^4+1,2x^3-0,5x^2$

$5)\ \ (15x^4-7x^3)-(19x^4-9x^3+4x^2)=\\\\=(15x^4-19x^4)+(-7x^3+9x^3)-4x^2=-4x^4+2x^3-4x^2\\\\6)\ \ x=-0,125=-\dfrac{1}{8}\ ,\ y=16\\\\\dfrac{4}{9}\, x^2-\Big(\dfrac{7}{9}\, xy-\dfrac{2}{9}\, x^2\Big)-\Big(\dfrac{2}{3}\, x^2+\dfrac{2}{9}\, xy\Big)=\\\\\\=\Big(\dfrac{4}{9}\, x^2+\dfrac{2}{9}\, x^2-\dfrac{2}{3}\, x^2\Big)+\Big(-\dfrac{7}{9}\, xy-\dfrac{2}{9}\, xy\Big)=\dfrac{4+2-4}{9}\, x^2+\dfrac{-7-2}{9} xy=$

$=\dfrac{2}{9}\, x^2-xy=\dfrac{2}{9}\, x\Big(x-y\Big)=-\dfrac{2}{9}\cdot \dfrac{1}{8} \cdot \Big(-\dfrac{1}{8}-16\Big)=-\dfrac{1}{36}\cdot (-\dfrac{129}{8})=\dfrac{129}{288}$