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C = \(\frac{2}{3}\sqrt{144}-\left(-\frac{3}{4}\right)\div\sqrt{\frac{225}{144}}\)
C = \(\frac{2}{3}.12+\frac{3}{4}\div\frac{5}{4}\)
C = \(8+\frac{3}{5}\)
C = \(8\frac{3}{5}\)
D = \(\frac{4^6.25^5-2^{12}.25^4}{2^{12}.5^8-10^8.64}\)
D = \(\frac{\left(2^2\right)^6.\left(5^2\right)^5-2^{12}.\left(5^2\right)^4}{2^{12}.5^8-\left(2.5\right)^8.2^6}\)
D = \(\frac{2^{12}.5^{10}-2^{12}.5^8}{2^{12}.5^8-2^8.5^8.2^6}\)
D = \(\frac{2^{12}.5^8.\left(25-1\right)}{2^{12}.5^8.\left(1-2^2\right)}\)
D = \(\frac{24}{-3}\)
D = \(-8\)
\(C=\frac{2}{3}\sqrt{144}-\left(\frac{-3}{4}\right):\sqrt{\frac{225}{144}}\)
\(=\frac{2}{3}\cdot12+\frac{3}{4}:\frac{5}{4}\)
\(=8+\frac{3}{4}\cdot\frac{4}{5}\)
\(=8+\frac{3}{5}\)
\(=\frac{40}{5}+\frac{3}{4}=\frac{43}{5}\)
\(D=\frac{4^6\cdot25^5-2^{12}\cdot25^4}{2^{12}\cdot5^8-10^8\cdot64}=\frac{\left(2^2\right)^6\cdot\left(5^2\right)^5-2^{12}\cdot\left(5^2\right)^4}{2^{12}\cdot5^8-\left(2\cdot5\right)^8\cdot2^6}\)
\(=\frac{2^{12}\cdot5^{10}-2^{12}\cdot5^8}{2^{12}\cdot5^8-2^{14}\cdot5^8}=\frac{5^8\left(2^{12}\cdot5^2-2^{12}\right)}{5^8\left(2^{12}-2^{14}\right)}\)
\(=\frac{2^{12}\cdot5^2-2^{12}}{2^{12}-2^{14}}=\frac{2^{12}\left(5^2-1\right)}{2^{12}\left(1-2^2\right)}=\frac{24}{-3}=-8\)
a)\(\sqrt{9.4}=\sqrt{36}=6;\sqrt{9}.\sqrt{4}=3.2=6\Rightarrow\sqrt{9.4}=\sqrt{9}.\sqrt{4}\)
b)\(\sqrt{169-144}=\sqrt{25}=5;\sqrt{169}-\sqrt{144}=13-12=1\Rightarrow\sqrt{169-144}>\sqrt{169}-\sqrt{144}\)
tra loi ho mik lun di mai ik hoc roi !chut chut chuit chut
\(\frac{1}{2}.\sqrt{144}+\sqrt{\frac{1}{9}}\\ =\frac{1}{2}.12+\frac{1}{3}\\ =6+\frac{1}{3}\\ =\frac{19}{3}\)
\(\frac{1}{2}.\sqrt{144}+\sqrt{\frac{1}{9}}\)
\(=\frac{1}{2}.12+\frac{1}{3}\)
\(=6+\frac{1}{3}\)
\(=\frac{19}{3}.\)
Chúc bạn học tốt!
Câu a:
\(\sqrt{26}\) + \(\sqrt{17}\) và 9
\(\sqrt{26}\) > \(\sqrt{25}\) = 5
\(\sqrt{17}\) > \(\sqrt{16}\) = 4
Cộng vế với vế ta có:
\(\sqrt{26}\) + \(\sqrt{17}\) > 5+ 4 = 9
Vậy \(\sqrt{26}\) + \(\sqrt{17}\) > 9
Câu b:
\(\sqrt8\) - \(\sqrt5\) và 1
\(\sqrt5\) > \(\sqrt4\) = 2
- \(\sqrt5\) < - 2 (nhân cả hai vế của bất đẳng thức với cùng một số âm thì bất đẳng thức đổi chiều)
- \(\sqrt5\) < - 2 (chứng minh trên)
\(\sqrt8\) < \(\sqrt9\) = 3
Cộng vế với vế ta có:
\(\sqrt8\) - \(\sqrt5\) < - 2 + 3
\(\sqrt8\) - \(\sqrt5\) < 1
Vậy \(\sqrt8\) - \(\sqrt5\) < 1
\(b,\sqrt{225}-\frac{1}{\sqrt{5}}-1=15-\frac{1}{\sqrt{5}}-1\)
\(=\frac{15\sqrt{5}}{\sqrt{5}}-\frac{1}{\sqrt{5}}-\frac{\sqrt{5}}{\sqrt{5}}=\frac{15\sqrt{5}-1-\sqrt{5}}{\sqrt{5}}\)
\(=\frac{14\sqrt{5}-1}{\sqrt{5}}=\frac{\sqrt{5}\left(14\sqrt{5}-1\right)}{5}=\frac{70-\sqrt{5}}{5}\)
Bài 1:
a) Ta có: \(\left(0.125\right)\cdot\left(-3\cdot7\right)\cdot\left(-2\right)^3\)
\(=\frac{1}{8}\cdot\left(-21\right)\cdot\left(-8\right)\)
\(=\frac{1}{8}\cdot168\)
\(=21\)
b) Ta có: \(\sqrt{36}\cdot\sqrt{\frac{25}{16}}+\frac{1}{4}\)
\(=\sqrt{36\cdot\frac{25}{16}}+\frac{1}{4}\)
\(=\sqrt{\frac{225}{4}}+\frac{1}{4}\)
\(=\frac{15}{2}+\frac{1}{4}\)
\(=\frac{31}{4}\)
c) Ta có: \(\sqrt{\frac{4}{81}}:\sqrt{\frac{25}{81}}-1\frac{2}{5}\)
\(=\frac{2}{9}:\frac{5}{9}-\frac{7}{5}\)
\(=\frac{2}{5}-\frac{7}{5}=-1\)
d) Ta có: \(0,1\cdot\sqrt{225}\cdot\sqrt{\frac{1}{4}}\)
\(=0,1\cdot15\cdot\frac{1}{2}=\frac{3}{4}\)
\(a,\sqrt{64}-\sqrt{16}+\sqrt{\left(-5\right)^2}\)
\(=8+4+5\)
\(=17\)
\(b,\sqrt{49}+\sqrt{4}-\sqrt{9}.\sqrt{144}\)
\(=7+2-3.12\)
\(=9-36\)
\(=-27\)
12 and 15
đáp án là 12 và 15
\(12^2\)
\(\sqrt{144}=12\)
\(\sqrt{225}=15\)
$\sqrt{144} = 12$
$\sqrt{226}=15$