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阅读材料:像(5+3)(53)=2(\sqrt{5}+\sqrt{3})(\sqrt{5}-\sqrt{3})=2aa=a(a0)\sqrt{a}•\sqrt{a}=a(a≥0)(b+1)(b1)=b1(b0)(\sqrt{b}+1)(\sqrt{b}-1)=b-1(b≥0)\ldots两个含有二次根式的代数式相乘,积不含有二次根式,我们称这两个代数式互为有理化因式.例如3\sqrt{3}3\sqrt{3},2+1\sqrt{2}+121\sqrt{2}-1,3+35\sqrt{3}+3\sqrt{5}335\sqrt{3}-3\sqrt{5}等都是互为有理化因式.
在进行二次根式计算时,利用有理化因式,可以化去分母中的根号.
例如:123=323×3=362+121=(2+1)2(21)(2+1)=3+22\frac{1}{2\sqrt{3}}=\frac{\sqrt{3}}{2\sqrt{3}×\sqrt{3}}=\frac{\sqrt{3}}{6};\frac{\sqrt{2}+1}{\sqrt{2}-1}=\frac{(\sqrt{2}+1)^2}{(\sqrt{2}-1)(\sqrt{2}+1)}=3+2\sqrt{2}.
解答下列问题:
(1)23+5(1)2\sqrt{3}+5与______互为有理化因式,将325\frac{3}{2\sqrt{5}}分母有理化得______;
(2)(2)①比较大小:20242023\sqrt{2024}-\sqrt{2023}______20232022(\sqrt{2023}-\sqrt{2022}(>\gt,<\lt,==,\geqslant\leqslant中的一种)
②计算下列式子的值:12+1+13+2+14+3++12024+2023\frac{1}{\sqrt{2}+1}+\frac{1}{\sqrt{3}+\sqrt{2}}+\frac{1}{\sqrt{4}+\sqrt{3}}+…+\frac{1}{\sqrt{2024}+\sqrt{2023}}
(3)(3)已知正整数aa,bb满足a21b2=232\frac{a}{\sqrt{2}-1}-\frac{b}{\sqrt{2}}=2-3\sqrt{2},求aa,bb的值.
知识点:分式的基本性质、约分、分式的加减法章节:第18章 分式 / 18.1 分式及其基本性质 / 18.1.2 分式的基本性质

答案与解析

答案

(1)23+5\left(1\right)2\sqrt{3}+52352\sqrt{3}-5互为有理化因式,将325\frac{3}{2\sqrt{5}}分母有理化得3510\frac{3\sqrt{5}}{10}
故答案为:2352\sqrt{3}-53510\frac{3\sqrt{5}}{10}
(2)(2)20242023=12024+2023\because \sqrt{2024}-\sqrt{2023}=\frac{1}{\sqrt{2024}+\sqrt{2023}}20232022=12023+2022\sqrt{2023}-\sqrt{2022}=\frac{1}{\sqrt{2023}+\sqrt{2022}}
12024+2023<12023+2022\frac{1}{\sqrt{2024}+\sqrt{2023}} \lt \frac{1}{\sqrt{2023}+\sqrt{2022}}
20242023<20232022\therefore \sqrt{2024}-\sqrt{2023} \lt \sqrt{2023}-\sqrt{2022}
故答案为:<\lt.
②原式=21+32+43++20242023=\sqrt{2}-1+\sqrt{3}-\sqrt{2}+\sqrt{4}-\sqrt{3}+\cdot \cdot \cdot +\sqrt{2024}-\sqrt{2023}
=20241=\sqrt{2024}-1
=25061=2\sqrt{506}-1
(3)a21b2=232(3)\because \frac{a}{\sqrt{2}-1}-\frac{b}{\sqrt{2}}=2-3\sqrt{2}
(2+1)a22b=232\therefore (\sqrt{2}+1)a-\frac{\sqrt{2}}{2}b=2-3\sqrt{2}
(a12b+3)2+a2=0(a-\frac{1}{2}b+3)\sqrt{2}+a-2=0
a12b+3=0\therefore a-\frac{1}{2}b+3=0a2=0a-2=0
解得a=2a=2b=10b=10.
aa的值是22bb的值是1010.

解析

(1)23+5\left(1\right)2\sqrt{3}+52352\sqrt{3}-5互为有理化因式,将325\frac{3}{2\sqrt{5}}分母有理化得3510\frac{3\sqrt{5}}{10}
故答案为:2352\sqrt{3}-53510\frac{3\sqrt{5}}{10}
(2)(2)20242023=12024+2023\because \sqrt{2024}-\sqrt{2023}=\frac{1}{\sqrt{2024}+\sqrt{2023}}20232022=12023+2022\sqrt{2023}-\sqrt{2022}=\frac{1}{\sqrt{2023}+\sqrt{2022}}
12024+2023<12023+2022\frac{1}{\sqrt{2024}+\sqrt{2023}} \lt \frac{1}{\sqrt{2023}+\sqrt{2022}}
20242023<20232022\therefore \sqrt{2024}-\sqrt{2023} \lt \sqrt{2023}-\sqrt{2022}
故答案为:<\lt.
②原式=21+32+43++20242023=\sqrt{2}-1+\sqrt{3}-\sqrt{2}+\sqrt{4}-\sqrt{3}+\cdot \cdot \cdot +\sqrt{2024}-\sqrt{2023}
=20241=\sqrt{2024}-1
=25061=2\sqrt{506}-1
(3)a21b2=232(3)\because \frac{a}{\sqrt{2}-1}-\frac{b}{\sqrt{2}}=2-3\sqrt{2}
(2+1)a22b=232\therefore (\sqrt{2}+1)a-\frac{\sqrt{2}}{2}b=2-3\sqrt{2}
(a12b+3)2+a2=0(a-\frac{1}{2}b+3)\sqrt{2}+a-2=0
a12b+3=0\therefore a-\frac{1}{2}b+3=0a2=0a-2=0
解得a=2a=2b=10b=10.
aa的值是22bb的值是1010.

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