Упр.11.16 ГДЗ Мордкович Семенов 8 класс (Алгебра)

а) (a^3 b^4 c)/(ab^2 c);
б) (12x^2 yz^5)/(18xy^2 z^5 );
в) (a + b)/((a — b)(a + b));
г) (x — y)^2/((x — y)(x + y));
д) (2a — 4)/(a(a — 2));
е) (3y + 9)/((y — 3)(y + 3)).

1. $$\frac{a^3b^4c}{ab^2c}=\frac{a^3}{a}\cdot\frac{b^4}{b^2}\cdot\frac{c}{c}=a^2b^2.$$
2. $$\frac{12x^2yz^5}{18xy^2z^5}=\frac{12}{18}\cdot\frac{x^2}{x}\cdot\frac{y}{y^2}\cdot\frac{z^5}{z^5}=\frac{2x}{3y}.$$
3. $$\frac{a+b}{(a-b)(a+b)}=\frac{1}{a-b}.$$
4. $$\frac{(x-y)^2}{(x-y)(x+y)}=\frac{x-y}{x+y}.$$
5. $$\frac{2a-4}{a(a-2)}=\frac{2(a-2)}{a(a-2)}=\frac{2}{a}.$$
6. $$\frac{3y+9}{(y-3)(y+3)}=\frac{3(y+3)}{(y-3)(y+3)}=\frac{3}{y-3}.$$

Ответ

а) $$a^2b^2$$; б) $$\frac{2x}{3y}$$; в) $$\frac{1}{a-b}$$; г) $$\frac{x-y}{x+y}$$; д) $$\frac{2}{a}$$; е) $$\frac{3}{y-3}$$.