Упр.353 ГДЗ Мерзляк Полонский 7 класс (Алгебра)

1) 2а и 5b; 2) -m и 4n; 3) 6x и -8у^2; 4) -1/7 x^3 и -7x^2. Упростите выражение:
1) 3m2n3 * 0,4mn3;
2) 7*1/3*b3c2*9/11*a4b5;
3) -5x4y2z8 * (-0,8x6y8z2);
4) -5*3/7*abc*3,5a12b10c.

1. $$2a \cdot 5b = 2 \cdot 5 \cdot ab = 10ab.$$
2. $$-m \cdot 4n = -4mn.$$
3. $$6x \cdot (-8y^2) = -6 \cdot 8 \cdot xy^2 = -48xy^2.$$
4. $$-\frac{1}{7}x^3 \cdot (-7x^2) = \frac{1}{7} \cdot 7 \cdot x^3 \cdot x^2 = x^5.$$
5. $$3m^2n \cdot 0{,}4mn^3 = 1{,}2m^3n^4.$$
6. $$7\frac{1}{3}b^3c^2 \cdot \frac{9}{11}a^4b^5 = \frac{22}{3}\cdot \frac{9}{11}a^4b^8c^2 = 6a^4b^8c^2.$$
7. $$-5x^4y^2z^8 \cdot (-0{,}8x^6y^8z^2) = 4x^{10}y^{10}z^{10}.$$
8. $$-5\frac{3}{7}abc \cdot 3{,}5a^{12}b^{10}c = -19a^{13}b^{11}c^2.$$

Ответ

1) $$10ab$$; 2) $$-4mn$$; 3) $$-48xy^2$$; 4) $$x^5$$; 5) $$1{,}2m^3n^4$$; 6) $$6a^4b^8c^2$$; 7) $$4x^{10}y^{10}z^{10}$$; 8) $$-19a^{13}b^{11}c^2$$.