Упр.8.9 ГДЗ Мерзляк Поляков 7 класс (Алгебра)

1) 0,6a^4 b^3•4a^2 b;
2)-2,8x^2 y^5•0,5x^4 y^6;
3) 13c^2 d•(-3cd);
4) 0,7x^6 y^9•0,3xy;
5)-3/20 p^2 q^8•40/81 p^8 q^2;
6)-6 1/2 mn^8 p^11•3 5/13 m^5 n^5.

1. $$0{,}6a^4b^3 \cdot 4a^2b = (0{,}6 \cdot 4)a^{4+2}b^{3+1} = 2{,}4a^6b^4.$$
2. $$-2{,}8x^2y^5 \cdot 0{,}5x^4y^6 = (-2{,}8 \cdot 0{,}5)x^{2+4}y^{5+6} = -1{,}4x^6y^{11}.$$
3. $$13c^2d \cdot (-3cd) = -39c^{2+1}d^{1+1} = -39c^3d^2.$$
4. $$0{,}7x^6y^9 \cdot 0{,}3xy = (0{,}7 \cdot 0{,}3)x^{6+1}y^{9+1} = 0{,}21x^7y^{10}.$$
5. $$ -\frac{3}{20}p^2q^8 \cdot \frac{40}{81}p^8q^2 = -\frac{3 \cdot 40}{20 \cdot 81}p^{2+8}q^{8+2} = -\frac{2}{27}p^{10}q^{10}. $$
6. $$ -6\frac{1}{2}mn^8p^{11} \cdot 3\frac{5}{13}m^5n^5 = -\frac{13}{2}mn^8p^{11} \cdot \frac{44}{13}m^5n^5 = -22m^{1+5}n^{8+5}p^{11} = -22m^6n^{13}p^{11}. $$

Ответ

1) $$2{,}4a^6b^4$$;
2) $$-1{,}4x^6y^{11}$$;
3) $$-39c^3d^2$$;
4) $$0{,}21x^7y^{10}$$;
5) $$-\frac{2}{27}p^{10}q^{10}$$;
6) $$-22m^6n^{13}p^{11}$$.