一、选择题(每小题5分,共20分)
1.(2025·宜兴期末)下列各式中是最简二次根式的是 (
A.$\sqrt{8}$
B.$\frac{1}{\sqrt{2}}$
C.$\sqrt{\frac{1}{2}}$
D.$\sqrt{5}$
1.(2025·宜兴期末)下列各式中是最简二次根式的是 (
D
)A.$\sqrt{8}$
B.$\frac{1}{\sqrt{2}}$
C.$\sqrt{\frac{1}{2}}$
D.$\sqrt{5}$
答案:1.D
2.等式"(
A.6
B.3
C.$3\sqrt{2}$
D.$\sqrt{6}$
6
)÷$\sqrt{18}$=$\sqrt{2}$"中,括号内应填入 (A
)A.6
B.3
C.$3\sqrt{2}$
D.$\sqrt{6}$
答案:2.A
3.若$\sqrt{\frac{x+1}{2-x}}=\frac{\sqrt{x+1}}{\sqrt{2-x}}$成立,则x的值可以是 (
A.-2
B.0
C.2
D.3
B
)A.-2
B.0
C.2
D.3
答案:3.B
4.(2025·九龙坡区期末)计算$(\sqrt{5}-2)^{2025}(2+\sqrt{5})^{2024}$的正确结果为 (
A.1
B.-1
C.$2+\sqrt{5}$
D.$\sqrt{5}-2$
D
)A.1
B.-1
C.$2+\sqrt{5}$
D.$\sqrt{5}-2$
答案:4.D
二、填空题(每小题5分,共20分)
5.比较大小:$2\sqrt{3}\_\_\_\_\_\_3\sqrt{2}$.
5.比较大小:$2\sqrt{3}\_\_\_\_\_\_3\sqrt{2}$.
答案:5.<
6.已知$\sqrt{20a}$是整数,则满足条件的最小正整数a的值是
5
.答案:6.5
7.(2025·常熟期末)计算$\sqrt{3}÷\sqrt{2}×2\sqrt{5}÷\sqrt{\frac{1}{10}}$的结果为
$10\sqrt{3}$
.答案:7.$10\sqrt{3}$
8.若x,y为实数,且$y<\sqrt{x-1}+\sqrt{1-x}+3$,化简:$|y-3|-\sqrt{y^{2}-8y+16}=$
-1
.答案:8.-1
三、解答题(共60分)
9.(每小题4分,共16分)化简:
(1)$\sqrt{1.5}$; (2)$\sqrt{\frac{9}{50}}$; (3)$\frac{\sqrt{48}}{\sqrt{6}}$; (4)$6\sqrt{\frac{1}{3}}$.
9.(每小题4分,共16分)化简:
(1)$\sqrt{1.5}$; (2)$\sqrt{\frac{9}{50}}$; (3)$\frac{\sqrt{48}}{\sqrt{6}}$; (4)$6\sqrt{\frac{1}{3}}$.
答案:9.解:(1)原式=$\sqrt{\frac{3}{2}}=\frac{\sqrt{6}}{2}$.(2)原式=$\frac{\sqrt{9}}{\sqrt{50}}=\frac{3}{5\sqrt{2}}=\frac{3\sqrt{2}}{10}$.
(3)原式=$\sqrt{\frac{48}{6}}=\sqrt{8}=2\sqrt{2}$.(4)原式=$6×\frac{\sqrt{3}}{3}=2\sqrt{3}$.
(3)原式=$\sqrt{\frac{48}{6}}=\sqrt{8}=2\sqrt{2}$.(4)原式=$6×\frac{\sqrt{3}}{3}=2\sqrt{3}$.
10.(每小题5分,共20分)计算:
(1)$\sqrt{30}÷\sqrt{3}×\sqrt{2}$; (2)$\sqrt{27}×\sqrt{50}÷\sqrt{6}$;
(3)$\sqrt{2}×\frac{\sqrt{6}}{3}÷\frac{4}{\sqrt{3}}$; (4)$\sqrt{\frac{1}{6}}×\sqrt{96}÷\sqrt{6}$.
(1)$\sqrt{30}÷\sqrt{3}×\sqrt{2}$; (2)$\sqrt{27}×\sqrt{50}÷\sqrt{6}$;
(3)$\sqrt{2}×\frac{\sqrt{6}}{3}÷\frac{4}{\sqrt{3}}$; (4)$\sqrt{\frac{1}{6}}×\sqrt{96}÷\sqrt{6}$.
答案:10.解:(1)原式=$\sqrt{30÷3×2}=\sqrt{20}=2\sqrt{5}$.
(2)原式=$3\sqrt{3}×5\sqrt{2}×\sqrt{\frac{1}{6}}=15$.
(3)原式=$\frac{2\sqrt{3}}{3}×\frac{\sqrt{3}}{4}=\frac{1}{2}$.
(4)原式=$\sqrt{\frac{1}{6}×96÷6}=\sqrt{\frac{96}{6×6}}=\frac{4\sqrt{6}}{6}=\frac{2\sqrt{6}}{3}$.
(2)原式=$3\sqrt{3}×5\sqrt{2}×\sqrt{\frac{1}{6}}=15$.
(3)原式=$\frac{2\sqrt{3}}{3}×\frac{\sqrt{3}}{4}=\frac{1}{2}$.
(4)原式=$\sqrt{\frac{1}{6}×96÷6}=\sqrt{\frac{96}{6×6}}=\frac{4\sqrt{6}}{6}=\frac{2\sqrt{6}}{3}$.