2026年同步练习册河北教育出版社七年级数学下册冀教版第68页答案
(1)计算 $6x^{3}· x^{2}$ 的结果是 (
B
)

A.$6x$
B.$6x^{5}$
C.$6x^{6}$
D.$6x^{9}$

答案

1.(1)B
(2)下列计算中,正确的有 (
B
)
①$3x^{3}· (-2x^{2})=-6x^{5};$
②$3a^{2}· 4a^{2}=12a^{2};$
③$3b^{3}· 8b^{3}=24b^{9};$
④$-3x· 2xy=6x^{2}y.$

A.0个
B.1个
C.2个
D.3个

答案

1.(2)B
(3)下列计算中,正确的是 (
D
)

A.$2a^{2}· (-a^{3})=-6a^{6}$
B.$6x^{2}· 3xy^{4}=9x^{3}y^{4}$
C.$-2xy^{2}· (-4xy)=-8x^{2}y^{3}$
D.$-3a^{3}b· (-3ab)=9a^{4}b^{2}$

答案

1.(3)D
(1)$2a· 3a=\_\_\_\_\_\_.$
6a²

答案

2.(1)$6a^{2}$
(2)$4xy· 5x^{2}yz=\_\_\_\_\_\_.$
20x³y²z

答案

2.(2)$20x^{3}y^{2}z$
(3)$3a^{3}b^{4}· (-2b^{3}c^{2})=\_\_\_\_\_\_.$
-6a³b⁷c²

答案

2.(3)$-6a^{3}b^{7}c^{2}$
(4)$2x^{3}y· (-2x^{2}y)^{2}=\_\_\_\_\_\_.$
8x⁷y³

答案

2.(4)$8x^{7}y^{3}$
(5)$\frac{2}{3}abc^{2}· (-\frac{1}{2}b^{3}c)=\_\_\_\_\_\_.$

答案

2.(5)$-\frac{1}{3}ab^{4}c^{3}$
(6)$-2a·\_\_\_\_\_\_\frac{1}{2}ab^{2}· 3a^{2}bc=\_\_\_\_\_\_.$

答案

2.(6)$-3a^{4}b^{3}c$
(7)$(-\frac{1}{2}ab^{2})^{2}· (-5abc)=\_\_\_\_\_\_.$
-5/4a³b⁵c

答案

2.(7)$-\frac{5}{4}a^{3}b^{5}c$
(8)若单项式$-6x^{2}y^{m}$与$\frac{1}{3}x^{n-1}y^{3}$是同类项,则这两个单项式的积是
-2x⁴y⁶
.

答案

2.(8)$-2x^{4}y^{6}$
3. 计算.
(1)$(-5x^{2}y)· (-4x^{3}y^{2});$
(2)$(-3ab^{2}c)· (-a^{2}c^{2})^{2};$
(3)$(-4x^{2}y)· (-x^{3}y^{2})· \frac{1}{2}y^{3};$
(4)$2mnp· (-\frac{1}{2}mn)· (-3np);$
(5)$(-ab)^{3}· (-a^{2}b)· (-a^{2}bc)^{2};$
(6)$\frac{1}{3}a^{3}b^{2}· (-6a^{2}b^{3})+(-2a^{2}b)^{2}· (-\frac{1}{2}ab^{3}).$

答案

3. (1)$20x^{5}y^{3}$ (2)$-3a^{5}b^{2}c^{5}$
(3)$2x^{5}y^{6}$ (4)$3m^{2}n^{3}p^{2}$
(5)$a^{9}b^{6}c^{2}$ (6)$-4a^{5}b^{5}$