1. $(-a^{2})^{3} ÷ a$ 等于 (
A.$-a^{6}$
B.$a^{6}$
C.$-a^{5}$
D.$a^{5}$
C
)A.$-a^{6}$
B.$a^{6}$
C.$-a^{5}$
D.$a^{5}$
答案:C
解析:
$(-a^{2})^{3} ÷ a = -a^{6} ÷ a = -a^{5}$,C
2. 下列计算正确的是 (
A.$a^{2m} ÷ a^{m} = a^{2}$
B.$x^{6} ÷ x ÷ x^{2} = x^{4}$
C.$2^{100} ÷ 2^{99} = 2$
D.$a^{2n} ÷ a^{2} = a^{n}$
C
)A.$a^{2m} ÷ a^{m} = a^{2}$
B.$x^{6} ÷ x ÷ x^{2} = x^{4}$
C.$2^{100} ÷ 2^{99} = 2$
D.$a^{2n} ÷ a^{2} = a^{n}$
答案:C
解析:
A.$a^{2m} ÷ a^{m} = a^{2m - m} = a^{m}$,故A错误;
B.$x^{6} ÷ x ÷ x^{2} = x^{6 - 1 - 2} = x^{3}$,故B错误;
C.$2^{100} ÷ 2^{99} = 2^{100 - 99} = 2^{1} = 2$,故C正确;
D.$a^{2n} ÷ a^{2} = a^{2n - 2}$,故D错误。
答案:C
B.$x^{6} ÷ x ÷ x^{2} = x^{6 - 1 - 2} = x^{3}$,故B错误;
C.$2^{100} ÷ 2^{99} = 2^{100 - 99} = 2^{1} = 2$,故C正确;
D.$a^{2n} ÷ a^{2} = a^{2n - 2}$,故D错误。
答案:C
3. 下列运算正确的是 (
A.$m^{6} ÷ m^{2} = m^{3}$
B.$a^{12} ÷ a^{3} = a^{4}$
C.$a^{6} ÷ a^{3} = a^{3}$
D.$6a^{8} ÷ 3a^{2} = 2a^{4}$
C
)A.$m^{6} ÷ m^{2} = m^{3}$
B.$a^{12} ÷ a^{3} = a^{4}$
C.$a^{6} ÷ a^{3} = a^{3}$
D.$6a^{8} ÷ 3a^{2} = 2a^{4}$
答案:C
解析:
A.$m^{6} ÷ m^{2} = m^{6-2}=m^{4}\neq m^{3}$
B.$a^{12} ÷ a^{3} = a^{12-3}=a^{9}\neq a^{4}$
C.$a^{6} ÷ a^{3} = a^{6-3}=a^{3}$
D.$6a^{8} ÷ 3a^{2} = (6÷3)a^{8-2}=2a^{6}\neq 2a^{4}$
C
B.$a^{12} ÷ a^{3} = a^{12-3}=a^{9}\neq a^{4}$
C.$a^{6} ÷ a^{3} = a^{6-3}=a^{3}$
D.$6a^{8} ÷ 3a^{2} = (6÷3)a^{8-2}=2a^{6}\neq 2a^{4}$
C
4. 计算 $10^{6} × (10^{2})^{3} ÷ 10^{4}$ 的结果是 (
A.$10^{3}$
B.$10^{7}$
C.$10^{8}$
D.$10^{9}$
C
)A.$10^{3}$
B.$10^{7}$
C.$10^{8}$
D.$10^{9}$
答案:C
解析:
$10^{6} × (10^{2})^{3} ÷ 10^{4}$
$=10^{6} × 10^{6} ÷ 10^{4}$
$=10^{6+6-4}$
$=10^{8}$
C
$=10^{6} × 10^{6} ÷ 10^{4}$
$=10^{6+6-4}$
$=10^{8}$
C
5. 计算:
(1) $2^{10} ÷ 2^{5}$; (2) $(-\frac{3}{2})^{5} ÷ (-\frac{3}{2})^{2}$;
(3) $b^{7} ÷ b^{4}$; (4) $(-x)^{6} ÷ (-x)^{3}$;
(5) $a^{12} ÷ a^{2}$; (6) $(a^{3})^{3} ÷ (a^{2})^{3}$;
(7) $(-\frac{2}{5}x)^{3} ÷ (-\frac{2}{5}x)$; (8) $(x + y)^{2n} ÷ (x + y)^{2n - 2}$.
(1) $2^{10} ÷ 2^{5}$; (2) $(-\frac{3}{2})^{5} ÷ (-\frac{3}{2})^{2}$;
(3) $b^{7} ÷ b^{4}$; (4) $(-x)^{6} ÷ (-x)^{3}$;
(5) $a^{12} ÷ a^{2}$; (6) $(a^{3})^{3} ÷ (a^{2})^{3}$;
(7) $(-\frac{2}{5}x)^{3} ÷ (-\frac{2}{5}x)$; (8) $(x + y)^{2n} ÷ (x + y)^{2n - 2}$.
答案:
(1) 32;
(2)$-\dfrac{27}{8}$;
(3)$b^{3}$;
(4)$-x^{3}$;
(5)$a^{10}$;
(6)$a^{3}$;
(7)$\dfrac{4}{25}x^{2}$;
(8)$x^{2}+2xy+y^{2}$
(1) 32;
(2)$-\dfrac{27}{8}$;
(3)$b^{3}$;
(4)$-x^{3}$;
(5)$a^{10}$;
(6)$a^{3}$;
(7)$\dfrac{4}{25}x^{2}$;
(8)$x^{2}+2xy+y^{2}$