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\(=4x^2y^6\cdot\left(-x^2y\right)\cdot\left(-8\right)x^3y^3z^3=32x^7y^{10}z^3\)
![](https://rs.olm.vn/images/avt/0.png?1311)
\(\Leftrightarrow3^{x-1}+5\cdot3^{x-1}=162\\ \Leftrightarrow3^{x-1}=162:6=27=3^3\\ \Leftrightarrow x-1=3\Leftrightarrow x=4\)
\(\Leftrightarrow3^{x-1}=162:6=27\)
\(\Leftrightarrow x=4\)
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a) -37/946 < 0
0 < (-1)/(-8)
-37/946 < -1/(-8)
b) -1987/(-1986) > 1
1 > -1984/(-1985)
-1987/(-1986) > -1994/(-1985)
c) -23/12 > -24/12 = -4/2
-4/2 > -5/2
-23/12 > -5/2
d) -24/25 < -23/25
-23/25 < -23/27
-24/25 < -23/27
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Bài 3:
Áp dụng tính chất của dãy tỉ số bằng nhau, ta được:
\(\dfrac{a}{2}=\dfrac{b}{5}=\dfrac{a+b}{2+5}=\dfrac{70}{7}=10\)
Do đó: a=20; b=50
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Bài 2:
=10-7=3
Bài 3:
Áp dụng tính chất của dãy tỉ số bằng nhau, ta được:
\(\dfrac{x}{7}=\dfrac{y}{3}=\dfrac{x-y}{7-3}=\dfrac{-16}{4}=-4\)
Do đó: x=-28; y=-12
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a: \(-6\cdot\left(-\dfrac{2}{3}\right)\cdot0.25=6\cdot\dfrac{2}{3}\cdot\dfrac{1}{4}=4\cdot\dfrac{1}{4}=1\)
b: \(\dfrac{-15}{4}\cdot\dfrac{-7}{15}\cdot\left(-2\dfrac{2}{5}\right)\)
\(=\dfrac{7}{4}\cdot\dfrac{12}{5}\)
\(=\dfrac{84}{20}=\dfrac{21}{5}\)
c: \(\left(-2\dfrac{1}{5}\right)\cdot\left(-\dfrac{9}{11}\right)\cdot\left(-\dfrac{1}{14}\right)\cdot\dfrac{2}{5}\)
\(=-\dfrac{11}{5}\cdot\dfrac{2}{5}\cdot\dfrac{9}{11}\cdot\dfrac{1}{14}\)
\(=-\dfrac{11}{11}\cdot\dfrac{2}{14}\cdot\dfrac{9}{25}\)
\(=-\dfrac{9}{175}\)
\(a,=4\cdot0,25=1\\ b,=\dfrac{7}{4}\cdot\left(-\dfrac{12}{5}\right)=-\dfrac{21}{5}\\ c,=\left(-\dfrac{11}{5}\right)\left(-\dfrac{9}{11}\right)\left(-\dfrac{15}{14}\right)\cdot\dfrac{2}{5}\\ =\dfrac{9}{5}\cdot\left(-\dfrac{15}{14}\right)\cdot\dfrac{2}{5}=-\dfrac{27}{14}\cdot\dfrac{2}{5}=-\dfrac{27}{35}\\ d,=\left(-\dfrac{11}{2}\right)\left(-\dfrac{1}{2}\right)+\dfrac{4}{9}=\dfrac{11}{4}+\dfrac{4}{9}=\dfrac{115}{36}\\ e,=\dfrac{5}{4}\cdot\left(-\dfrac{8}{15}\right)-\dfrac{3}{5}-\dfrac{3}{10}=-\dfrac{2}{3}-\dfrac{3}{5}-\dfrac{3}{10}=-\dfrac{47}{30}\)
\(f,B=\dfrac{2^{12}\cdot3^{10}+2^9\cdot3^9\cdot2^3\cdot3\cdot5}{2^{12}\cdot3^{12}-2^{11}\cdot3^{11}}=\dfrac{2^{12}\cdot3^{10}\left(1+5\right)}{2^{11}\cdot3^{11}\left(6-1\right)}=\dfrac{2\cdot6}{5\cdot3}=\dfrac{4}{5}\\ g,=\dfrac{5}{8}+\dfrac{9}{4}\cdot\dfrac{5}{3}-\dfrac{5}{24}=\dfrac{5}{8}+\dfrac{15}{4}-\dfrac{5}{24}=\dfrac{25}{6}\\ h,=\dfrac{49}{38}\cdot\left(\dfrac{152}{11}-\dfrac{57}{11}\right):\dfrac{245}{418}=\dfrac{49}{38}\cdot\dfrac{418}{245}\cdot\dfrac{95}{11}=\dfrac{95\cdot11}{5\cdot11}=19\\ k,=\dfrac{11}{30}+\dfrac{18}{35}\cdot\dfrac{35}{54}-\dfrac{18}{35}\cdot\dfrac{49}{18}-\dfrac{18}{35}\cdot\dfrac{28}{48}\\ =\dfrac{11}{30}+\dfrac{1}{3}-\dfrac{7}{5}-\dfrac{3}{10}=-1\)
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https://hoc24.vn/cau-hoi/giai-het-giup-mk-vs-a-huhu.2030470567354
làm hết r mà :vv
bài 1 :
\(a,2^3+3\left(\frac{1}{2}\right)^0-1+\left[\left(-2\right)^2:\frac{1}{2}\right].8\)
\(=8+3.1-1+\left(-4:\frac{1}{2}\right).8\)
\(=8+3-1+\left(-8\right).8\)
\(=10-64\)
\(=-54\)
\(b,2^3+3\left(\frac{1}{2009}\right)^0-2^2:4\)
\(=8+3.1-4:4\)
\(=8+3-1\)
\(=10\)
Bài 1 :
a) \(2^3+3.\left(\frac{1}{2}\right)^0-1+\left[\left(-2\right)^2:\frac{1}{2}\right].8\)
\(=8+3.1-1+\left(4.2\right).8\)
\(=8+3-1+64=74\)
b) \(2^3+3.\left(\frac{1}{2009}\right)^0-2^2:4\)
\(=8+3.1-4:4\)
= 8 + 3 - 1 = 10