1.So sánh hai số: \(a=15^{120}:25^{60}\) và \(b=2^{45}.2^{15}.4^{60}\)
2. Tính: \(\left(\frac{-3}{2}\right)^2-\left[\frac{1}{2}:2-\sqrt{81.}\left(\frac{-1}{2}\right)^2\right]\)
Mn giúp tôi vs nhiều bài wa lm ko hết lên đâu cầu cứu
1. Tìm x:
\(\left(\frac{4}{5}\right)^{2x+7}=\frac{625}{256}\)
2. So sánh:
\(a=15^{120}:25^{60}\)và \(b=2^{45}.2^{15}.4^{60}\)
\(a=\left(15^2\right)^{60}:25^{60}\)
\(a=225^{60}:25^{60}\)
\(a=\left(225:25\right)^{60}=9^{60}\)
\(b=2^{45}.2^{15}.2^{120}\)
\(b=2^{180}=8^{60}\)
vì \(8^{60}< 9^{60}\)nên b<a
1,\(\left(\frac{4}{5}\right)^{2x+7}=\left(\frac{4}{5}\right)^{-4}\)
\(\Rightarrow\)2x+7=-4
2x=-11
x=-5,5
Cho \(A=\frac{\left(3\frac{2}{15}+\frac{1}{15}\right):2\frac{1}{2}}{\left(5\frac{3}{7}-2\frac{1}{4}\right):4\frac{43}{56}}\)
\(B=\frac{1;2:\left(1\frac{1}{5}:1\frac{1}{4}\right)}{0,32+\frac{2}{25}}\)
So sánh A và B
Thực hiện phép tính
\(\frac{-1}{3}+\left(\frac{2}{3}\right)^3:\sqrt{\frac{64}{81}}-\left(-\frac{2}{5}\right)^0\)
\(15\frac{1}{5}:\left(\frac{-5}{7}\right)-25\frac{1}{5}.\left(\frac{-7}{5}\right)\)
\(\left(\frac{2}{5}\right)^6.\left(\frac{25}{4}\right)^2\)
\(\left(\frac{2}{5}\right)^6.\left(\frac{25}{4}\right)^2\)
\(=\left[\left(\frac{2}{5}\right)^3\right]^2.\left(\frac{25}{4}\right)^2\)
\(=\left[\left(\frac{2}{5}\right)^3.\frac{25}{4}\right]^2\)
\(=\left[\frac{8}{125}.\frac{25}{4}\right]^2\)
\(=\left(\frac{2}{5}\right)^2\)
\(=\frac{4}{25}\)
\(15\frac{1}{5}:\left(\frac{-5}{7}\right)-25\frac{1}{5}.\left(\frac{-7}{5}\right)\)
\(=15\frac{1}{5}.\frac{-7}{5}-25\frac{1}{5}.\frac{-7}{5}\)
\(=\frac{-7}{5}\left(15\frac{1}{5}-25\frac{1}{5}\right)\)
\(=\frac{-7}{5}.\left(-10\right)\)
\(=14\)
Tính nhanh:
\(\frac{\left(\frac{1}{14}-\frac{\sqrt{2}}{7}+\frac{3\sqrt{2}}{25}\right).\left(-\frac{4}{15}\right)}{\:\left(\frac{1}{10}+\frac{3\sqrt{2}}{25}-\frac{\sqrt{2}}{5}\right).\left(\frac{5}{7}\right)}\)
Thực hiện phép tính :
a)\(\frac{4}{7}-\frac{1}{14}+\left|\frac{-5}{21}\right|-\frac{-3}{7}\)
b) \(\frac{11}{15}.\frac{12}{13}-\frac{7}{15}+\frac{14}{15}.\frac{11}{13}\)
c)\(\left(\frac{3}{2}\right)^2-\left[\frac{1}{2}:2-\sqrt{81}.\left(-\frac{1}{2}\right)^2\right]\)
1, tim x bết:
,\(\frac{\left(-5^4\right).\left(-15^2\right)-5^4.\left(-3^2.5\right)}{\left(-3^4\right).25^2-\left(-15^2\right).225.5}\)\(:\)\(\frac{x}{5}\)\(=\frac{-1}{6}\)
2, cho A=\(\frac{20}{30}+\frac{20}{70}+\frac{20}{126}+...+\frac{20}{798}\)
B=\(\left(\frac{41}{2}.\frac{42}{2}.\frac{43}{2}...\frac{80}{2}\right):\left(1.3.5...79\right)\)
So sánh A và B.
3, Tính nhanh.
\(\frac{0,875+\frac{1}{2}-7\%-\frac{1}{58}}{\frac{1}{25}-\frac{1}{2}-\frac{2}{7}+\frac{2}{203}}\)\(-125\%\)
HELP ME PLEASE......
\(\frac{1}{3}\left(\sqrt{6}+\sqrt{5}\right)^2-\frac{1}{4}\sqrt{120}-2\sqrt{\frac{15}{2}}.\)
\(\left(\frac{1}{2}\sqrt{\frac{2}{3}}-\frac{3}{4}\sqrt{54}+\frac{1}{3}\sqrt{\frac{8}{3}}\right):\sqrt{\frac{81}{6}}\)
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Ta có: \(\frac{1}{3}\left(\sqrt{6}+\sqrt{5}\right)^2-\frac{1}{4}\sqrt{120}-2\sqrt{\frac{15}{2}}\)
\(=\frac{1}{3}\left(11+2\sqrt{30}\right)-\frac{\sqrt{30}}{2}-\sqrt{30}\)
\(=\frac{11}{3}+\frac{2}{3}\sqrt{30}-\frac{\sqrt{30}}{2}-\sqrt{30}\)
\(=\frac{11}{3}-\frac{5}{6}\sqrt{30}\)
\(=\frac{22-5\sqrt{30}}{6}\)
Ta có: \(\left(\frac{1}{2}\sqrt{\frac{2}{3}}-\frac{3}{4}\sqrt{54}+\frac{1}{3}\sqrt{\frac{8}{3}}\right)\div\sqrt{\frac{81}{6}}\)
\(=\left(\frac{\sqrt{6}}{6}-\frac{9\sqrt{6}}{4}+\frac{2\sqrt{6}}{9}\right)\div\frac{3\sqrt{6}}{2}\)
\(=-\frac{67\sqrt{6}}{36}\cdot\frac{2}{3\sqrt{6}}\)
\(=-\frac{67}{54}\)
tính
\(\left\{\left[\left(2\sqrt{2}\right)^2:2,4\right].\left[5,25:\left(\sqrt{7}\right)^2\right]\right\}:\left\{\left[2\frac{1}{7}:\frac{\left(\sqrt{5}\right)^2}{7}\right]:\left[2^3:\frac{\left(2\sqrt{2}\right)^2}{\sqrt{81}}\right]\right\}\)
tìm x,y,x
\(\sqrt{\left(x-\sqrt{2}\right)^2}+\sqrt{\left(y+\sqrt{2}\right)^2}+\left|x+y+z\right|=0\)
so sánh A và B:
\(A=\sqrt{225}-\frac{1}{\sqrt{5}}-1\) \(B=\sqrt{196}-\frac{1}{\sqrt{6}}\)
ai giải đc câu nào thì giải giúp với
Giúp mik với
Tính
a)\(\frac{2}{3}\sqrt{81}-\left(\frac{-3}{4}\right).\sqrt{\frac{9}{64}}+\left(\frac{\sqrt{2}}{3}\right)^2\)
b)\(\left(-\sqrt{\frac{5}{4}}\right)^2-\sqrt{\frac{9}{4}}:\left(-4,5\right)-\sqrt{\frac{25}{16}}.\sqrt{\frac{64}{9}}\)
c)\(-2^4-\left(-2\right)^2:\left(-\sqrt{\frac{16}{121}}\right)-\left(-\sqrt{\frac{2}{3}}\right)^2:\left(-2\frac{2}{3}\right)\)