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\(\dfrac{\left(\dfrac{2}{3}\right)^3\cdot\left(-\dfrac{3}{4}\right)^2\cdot\left(-1\right)^5}{\left(\dfrac{2}{5}\right)^2\cdot\left(-\dfrac{5}{12}\right)^3}\)\(=\dfrac{\dfrac{2^3\cdot\left(-3\right)^2\cdot\left(-1\right)}{3^3\cdot4^2}}{\dfrac{2^2\cdot\left(-5\right)^3}{5^2\cdot12^3}}\)
\(=\dfrac{\dfrac{2^3\cdot3^2\cdot\left(-1\right)}{3^3\cdot\left(2^2\right)^2}}{\dfrac{2^2\cdot\left(-5\right)^3}{5^2\cdot\left(2^2\cdot3\right)^3}}=\dfrac{\dfrac{2^3\cdot3^2\cdot\left(-1\right)}{3^3\cdot2^4}}{\dfrac{2^2\cdot5^2\cdot\left(-5\right)}{5^2\cdot2^6\cdot3^3}}=\dfrac{\dfrac{-1}{3\cdot2}}{\dfrac{-5}{2^4\cdot3^3}}\)
\(=\dfrac{-\dfrac{1}{6}}{27\cdot16}=-\dfrac{1}{6}:432=-\dfrac{1}{6}\cdot\dfrac{1}{432}=-\dfrac{1}{2592}\)
\(=\left(-2-\dfrac{7}{12}\right):\dfrac{15}{7}-\dfrac{1}{18}:\dfrac{15}{7}+\dfrac{20}{9}:\dfrac{15}{7}\)
\(=\dfrac{7}{15}\left(-2-\dfrac{7}{12}-\dfrac{1}{18}+\dfrac{20}{9}\right)\)
\(=\dfrac{7}{15}\cdot\dfrac{-72-21-2+80}{36}=\dfrac{7}{15}\cdot\dfrac{-15}{36}=\dfrac{-7}{36}\)
\(\left(-2\dfrac{7}{12}\right):2\dfrac{1}{7}-\dfrac{1}{18}:2\dfrac{1}{7}+2\dfrac{2}{9}:2\dfrac{1}{7}\)
\(=\left(-2\dfrac{7}{12}-\dfrac{1}{18}+2\dfrac{2}{9}\right):2\dfrac{1}{7}\)
\(=\left(\dfrac{-31}{12}-\dfrac{1}{18}+\dfrac{20}{9}\right):2\dfrac{1}{7}\)
\(=-\dfrac{5}{12}:\dfrac{15}{7}\)
\(=-\dfrac{5}{12}\cdot\dfrac{7}{15}\)
\(=-\dfrac{7}{36}\)
5: \(=3-\dfrac{1}{4}+\dfrac{2}{3}-5+\dfrac{1}{3}+\dfrac{6}{5}-6+\dfrac{7}{4}-\dfrac{3}{2}\)
\(=3-5-6+\dfrac{-1}{4}+\dfrac{7}{4}+\dfrac{2}{3}+\dfrac{1}{3}+\dfrac{6}{5}-\dfrac{3}{2}\)
\(=-8+\dfrac{3}{2}+1+\dfrac{-3}{10}\)
\(=-7+\dfrac{15-3}{10}=-7+\dfrac{6}{5}=-\dfrac{29}{5}\)
6: \(=6-\dfrac{2}{3}+\dfrac{1}{2}-5-\dfrac{5}{3}+\dfrac{3}{2}-3+\dfrac{7}{3}-\dfrac{5}{2}\)
\(=6-5-3-\dfrac{2}{3}-\dfrac{5}{3}+\dfrac{7}{3}+\dfrac{1}{2}+\dfrac{3}{2}-\dfrac{5}{2}\)
\(=-2-\dfrac{1}{2}=-\dfrac{5}{2}\)
7: \(=\dfrac{5}{3}-\dfrac{3}{7}+9-2-\dfrac{5}{7}+\dfrac{2}{3}+\dfrac{8}{7}-\dfrac{4}{3}-10\)
\(=9-2-10+\dfrac{5}{3}+\dfrac{2}{3}-\dfrac{4}{3}+\dfrac{-3}{7}-\dfrac{5}{7}+\dfrac{8}{7}\)
=-3+1
=-2
8: \(=8-\dfrac{9}{4}+\dfrac{2}{7}+6+\dfrac{3}{7}-\dfrac{5}{4}-3-\dfrac{2}{4}+\dfrac{9}{7}\)
\(=8+6-3+\dfrac{2}{7}+\dfrac{3}{7}+\dfrac{9}{7}-1-\dfrac{2}{4}\)
\(=11+2-1-\dfrac{1}{2}\)
=11+1/2
=11,5
\(\left(-12.\frac{2}{7}+\frac{8}{9}:\frac{7}{2}-\frac{2}{7}.\frac{5}{18}\right).\frac{7}{2}\)
\(=\left(-12.\frac{2}{7}+\frac{8}{9}.\frac{2}{7}-\frac{2}{7}.\frac{5}{18}\right).\frac{7}{2}\)
\(=\left[\frac{2}{7}.\left(-12+\frac{8}{9}-\frac{5}{18}\right)\right].\frac{7}{2}\)
\(=\left(\frac{2}{7}.-\frac{205}{18}\right).\frac{7}{2}\)
\(=\left(\frac{2}{7}.\frac{7}{2}\right).-\frac{205}{18}\)
\(=1.\left(-\frac{205}{18}\right)\)
\(=\left(-\frac{205}{18}\right)\)
a) -1/24 - [ 1/4 - ( 1/2 - 7/8 )]
= -1/24 - [ 1/4 +3/8 ]
= -1/24 - 5/8
= -2/3.
a) -1/24 - [ 1/4 - ( 1/2 - 7/8 )]
= -1/24 - [ 1/4 +3/8 ]
= -1/24 - 5/8
= -2/3.
a: \(2^7+\left(x-3^7\right)=5^7-4^7\)
=>\(128+x-2187=78125-16384\)
=>\(x-2059=61741\)
=>\(x=61741+2059=63800\)
c: \(7^2-\left(x+15\right)=5\cdot2^2\)
=>49-(x+15)=5*4=20
=>x+15=29
=>x=14
d: 7^3-7(13-x)=14
=>343-7(13-x)=14
=>7(13-x)=343-14=329
=>13-x=47
=>x=13-47=-34
a)\(2^2\div2^7\)
\(=2^{2-7}\)
\(=2^{-5}=-252\)
\(2^{-5}\)