\(a,\left(31\dfrac{6}{13}+5\dfrac{9}{41}\right)-36\dfrac{6}{13}\\ =\left(31-36\right)+\left(\dfrac{6}{13}-\dfrac{6}{13}\right)+5\dfrac{9}{41}\\ =-5+0+5\dfrac{9}{41}\\ =\left(-5+5\right)+\dfrac{9}{41}=\dfrac{9}{41}\)
\(b,\dfrac{5}{3}+\left(-\dfrac{2}{7}\right)-\left(-1,2\right)\\ =\dfrac{5}{3}-\dfrac{2}{7}+\dfrac{6}{5}\\ =\dfrac{5.35-2.15+6.21}{105}=\dfrac{271}{105}\\ c,0,25+\dfrac{3}{5}-\left(\dfrac{1}{8}-\dfrac{2}{5}+1\dfrac{1}{4}\right)=\dfrac{1}{4}+\dfrac{3}{5}-\dfrac{1}{8}+\dfrac{2}{5}-1\dfrac{1}{4}\\ =\left(-1\dfrac{1}{4}+\dfrac{1}{4}\right)+\left(\dfrac{3}{5}+\dfrac{2}{5}\right)-\dfrac{1}{8}=-1+1-\dfrac{1}{8}=-\dfrac{1}{8}\)
a) (31 6/13 + 5 9/41) - 36 6/13
= 409/13 + 214/41 - 474/13
= (409/13 - 474/13) + 214/41
= -5 + 214/41
= 9/41
b) 5/3 + (-2/7) - (-1,2)
= 5/3 - 2/7 + 6/5
= 29/21 + 6/5
= 271/105
c) 0,25 + 3/5 - (1/8 - 2/5 + 1 1/4)
= 1/4 + 3/5 - 1/8 + 2/5 - 5/4
= (1/4 - 5/4) + (3/5 + 2/5) - 1/8
= -1 + 1 - 1/8
= -1/8
\(a.\left[-\dfrac{6}{11}.\dfrac{11}{-6}\right].\dfrac{7}{10}.\left(-20\right)=1.7.\left(-2\right)=-14\)
\(b.\dfrac{-1}{2}:\dfrac{3}{4}.\dfrac{-7}{2}=\dfrac{7}{4}:\dfrac{3}{4}=\dfrac{7}{3}\)
\(c.\dfrac{93}{7}:-\dfrac{8}{9}+\dfrac{19}{7}:\dfrac{-8}{9}=\left(\dfrac{93}{7}+\dfrac{19}{7}\right):-\dfrac{8}{9}=\dfrac{-9}{8}.\dfrac{112}{7}=-18\)
a) \(=\left(13\dfrac{2}{7}+2\dfrac{5}{7}\right):\left(-\dfrac{8}{9}\right)\)
\(=16:\dfrac{-8}{9}=\dfrac{-8\cdot\left(-2\right)\cdot9}{-8}=-18\)
b)
\(=\left(\dfrac{-6}{11}\cdot\dfrac{11}{-6}\right)\cdot\dfrac{7\cdot10\cdot\left(-2\right)}{10}\)
\(=-14\)
c) \(=\dfrac{-1}{2}\cdot\dfrac{4}{3}\cdot\dfrac{-7}{2}\)
\(=\dfrac{-1\cdot2\cdot2\cdot\left(-7\right)}{2\cdot3\cdot2}=\dfrac{7}{3}\)
5) \(\left(-2\right)^2+\sqrt{36}-\sqrt{9}+\sqrt{25}\)
=\(4+6-3+5\)
=\(12\)
2) \(\dfrac{11}{25}.\left(-24,8\right)-\dfrac{11}{25}.75,2\)
=\(\dfrac{11}{25}.\left(-24,8-75,2\right)\)
=\(\dfrac{11}{25}.\left(-100\right)\)
=\(-44\)
*Trả lời :
a) \(-\dfrac{3}{4}.5\dfrac{3}{13}-0,75.\dfrac{36}{13}\)
= \(-\dfrac{3}{4}.\dfrac{68}{13}-\dfrac{3}{4}.\dfrac{36}{13}\)
=\(\dfrac{3}{4}.\dfrac{-68}{13}-\dfrac{3}{4}.\dfrac{36}{13}\)
=\(\dfrac{3}{4}.\cdot\left(\dfrac{-68}{13}-\dfrac{36}{13}\right)\)
=\(\dfrac{3}{4}.\left(-8\right)\)
= \(-6\)
b)\(4\dfrac{5}{9}:\left(-\dfrac{5}{7}\right)+\dfrac{49}{9}:\left(-\dfrac{5}{7}\right)\)
=\(\dfrac{41}{9}-\left(-\dfrac{5}{7}\right)+\dfrac{49}{9}:\left(-\dfrac{5}{7}\right)\)
=\(\left(\dfrac{41}{9}+\dfrac{49}{9}\right):\left(-\dfrac{5}{7}\right)\)
=\(\dfrac{90}{9}:\left(-\dfrac{5}{7}\right)\)
=\(10:\left(-\dfrac{5}{7}\right)\)
=\(-14\)
c)\(\left(-\dfrac{3}{5}+\dfrac{4}{9}\right):\dfrac{7}{11}+\left(-\dfrac{2}{5}+\dfrac{5}{9}\right):\dfrac{7}{11}\)
=\(\left(-\dfrac{3}{5}\right)+\dfrac{4}{9}:\dfrac{7}{11}+\left(-\dfrac{2}{5}\right)+\dfrac{5}{9}:\dfrac{7}{11}\)(áp dụng tính chất phá ngoặc )
=\(\left\{\left[-\dfrac{3}{5}+\left(-\dfrac{2}{5}\right)\right]+\left(\dfrac{4}{9}+\dfrac{5}{9}\right)\right\}:\dfrac{7}{11}\)
=\(\left(-\dfrac{5}{5}+\dfrac{9}{9}\right):\dfrac{7}{11}\)
=\(\left(-1+1\right):\dfrac{7}{11}\)
\(=0:\dfrac{7}{11}\)
=0.
d)\(\dfrac{6}{7}:\left(\dfrac{3}{26}-\dfrac{3}{13}\right)+\dfrac{6}{7}:\left(\dfrac{1}{10}-\dfrac{8}{5}\right)\)
=\(\dfrac{6}{7}:\left[\dfrac{3}{26}+\left(-\dfrac{6}{26}\right)\right]+\dfrac{6}{7}:\left[\dfrac{1}{10}+\left(-\dfrac{16}{10}\right)\right]\)
=\(\dfrac{6}{7}:\left(-\dfrac{3}{26}\right)+\dfrac{6}{7}:\left(-\dfrac{3}{2}\right)\)
=\(\dfrac{6}{7}:\left[\left(-\dfrac{3}{26}\right)+\left(-\dfrac{39}{26}\right)\right]\)
=\(\dfrac{6}{7}:\left(-\dfrac{21}{13}\right)\)
=\(-\dfrac{26}{49}\)
\(a.=\dfrac{1}{2}-\dfrac{1}{3}-\dfrac{5}{3}+\dfrac{3}{2}+\dfrac{7}{3}-\dfrac{5}{2}=\dfrac{1+3-5}{2}-\dfrac{2+5-7}{3}=\dfrac{-1}{2}\)
\(b.\left(\dfrac{3}{4}-1\dfrac{1}{6}\right)^2:\sqrt{\dfrac{25}{144}}=\left(-\dfrac{5}{12}\right)^2:\dfrac{5}{12}=\dfrac{5}{12}\)
Lời giải :
a ) \(1\dfrac{4}{23}+\dfrac{5}{21}-\dfrac{4}{23}+0,5+\dfrac{16}{21}\)
\(=\left(1\dfrac{4}{23}-\dfrac{4}{23}\right)+\left(\dfrac{5}{21}+\dfrac{16}{21}\right)+0,5\)
\(=2,5\)
b ) \(\dfrac{3}{7}.19\dfrac{1}{3}-\dfrac{3}{7}.33\dfrac{1}{3}\)
\(=\dfrac{3}{7}\left(19\dfrac{1}{3}-33\dfrac{1}{3}\right)\)
\(=\dfrac{3}{7}\left(19-33\right)\)
\(=\dfrac{3}{7}\left(-14\right)\)
\(=-6\)
c ) \(9\left(-\dfrac{1}{3}\right)^3+\dfrac{1}{3}\)
\(=9\left(-\dfrac{1}{27}\right)+\dfrac{1}{3}\)
\(=-\dfrac{1}{3}+\dfrac{1}{3}\)
\(=0\)
d ) \(15\dfrac{1}{4}\div\left(-\dfrac{5}{7}\right)-25\dfrac{1}{4}\div\left(-\dfrac{5}{7}\right)\)
\(=\left(15\dfrac{1}{4}-25\dfrac{1}{4}\right)\div\left(-\dfrac{5}{7}\right)\)
\(=-10\left(-\dfrac{7}{5}\right)\)
\(=14\)
a,\(\dfrac{5}{6}+\left(-\dfrac{1}{2}\right)+\dfrac{3}{4}\)
\(=\dfrac{10}{12}+\left(-\dfrac{6}{12}\right)+\dfrac{9}{12}\)
\(=\dfrac{10-6+9}{12}=\dfrac{13}{12}\)
b,\(\left(0,75-\dfrac{1}{3}\right):\dfrac{7}{15}\)
\(=\left(\dfrac{3}{4}-\dfrac{1}{3}\right):\dfrac{7}{15}\)
\(=\left(\dfrac{9}{12}-\dfrac{4}{12}\right):\dfrac{7}{15}\)
\(=\dfrac{5}{12}:\dfrac{7}{15}\)
\(=\dfrac{25}{28}\)
c,\(\dfrac{7}{12}-\dfrac{3}{4}.\dfrac{5}{6}\)
\(=\dfrac{7}{12}-\dfrac{5}{8}\)
\(=\dfrac{14}{24}-\dfrac{15}{24}\)
\(=-\dfrac{1}{24}\)
d,\(\left(2\dfrac{1}{3}+1\dfrac{3}{4}\right).\dfrac{12}{13}\)
\(=\left(\dfrac{7}{3}+\dfrac{7}{4}\right).\dfrac{12}{13}\)
\(=\left(\dfrac{28}{12}+\dfrac{21}{12}\right).\dfrac{12}{13}\)
\(=\dfrac{49}{12}.\dfrac{12}{13}\)
\(=\dfrac{49}{13}\)
a) \(\dfrac{5}{6}+\left(\dfrac{-1}{2}\right)+\dfrac{3}{4}\)
\(=\dfrac{10}{12}-\dfrac{6}{12}+\dfrac{9}{12}\)
\(=\dfrac{13}{12}\)
b) \(\left(0,75-\dfrac{1}{3}\right):\dfrac{7}{15}\)
\(=\left(\dfrac{3}{4}-\dfrac{1}{3}\right).\dfrac{15}{7}\)
\(=\left(\dfrac{9}{12}-\dfrac{4}{12}\right).\dfrac{15}{7}\)
\(=\dfrac{5}{12}.\dfrac{15}{7}\)
\(=\dfrac{25}{28}\)
c) \(\dfrac{7}{12}-\dfrac{3}{4}.\dfrac{5}{6}\)
\(=\dfrac{7}{12}-\dfrac{5}{8}\)
\(=\dfrac{14}{24}-\dfrac{15}{24}\)
\(=\dfrac{-1}{24}\)
d) \(\left(2\dfrac{1}{3}+1\dfrac{3}{4}\right).\dfrac{12}{13}\)
\(=\left(\dfrac{7}{3}+\dfrac{7}{4}\right).\dfrac{12}{13}\)
\(=\left(\dfrac{28}{12}+\dfrac{21}{12}\right).\dfrac{12}{13}\)
\(=\dfrac{49}{12}.\dfrac{12}{13}\)
\(=\dfrac{49}{13}\)
\(a,\dfrac{2}{3}.\dfrac{5}{4}-\dfrac{3}{4}.\dfrac{2}{3}=\dfrac{2}{3}.\left(\dfrac{5}{4}-\dfrac{3}{4}\right)=\dfrac{2}{3}.\dfrac{2}{4}=\dfrac{1}{3}\)
\(b,2.\left(\dfrac{-3}{2}\right)-\dfrac{7}{2}=-6.\dfrac{1}{2}-7.\dfrac{1}{2}=\left(-6-7\right).\dfrac{1}{2}=-13.\dfrac{1}{2}=\dfrac{-13}{2}\)
\(c,-\dfrac{3}{4}.5\dfrac{3}{13}-0,75.\dfrac{36}{13}=-\dfrac{3}{4}.\left(\dfrac{68}{13}-\dfrac{36}{13}\right)=-\dfrac{3}{4}.\dfrac{32}{13}=-\dfrac{24}{13}\)
a) \(\dfrac{2}{3}.\dfrac{5}{4}-\dfrac{3}{4}.\dfrac{2}{3}\)
\(=\dfrac{2}{3}.\left(\dfrac{5}{4}-\dfrac{3}{4}\right)\)
\(=\dfrac{2}{3}.\dfrac{2}{4}\)
\(=\dfrac{2}{3}.\dfrac{1}{2}\)
\(=\dfrac{1}{3}\)
b) \(2.\left(\dfrac{-3}{2}\right)^2-\dfrac{7}{2}\)
\(=2.\dfrac{9}{4}-\dfrac{7}{2}\)
\(=\dfrac{9}{2}-\dfrac{7}{2}\)
\(=\dfrac{2}{2}=1\)
c) \(-\dfrac{3}{4}.5\dfrac{3}{13}-0,75.\dfrac{36}{13}\)
\(=-\dfrac{3}{4}.\dfrac{68}{13}-\dfrac{3}{4}.\dfrac{36}{13}\)
\(=\dfrac{3}{4}.\dfrac{-68}{13}-\dfrac{3}{4}.\dfrac{36}{13}\)
\(=\dfrac{3}{4}.\left(\dfrac{-68}{13}-\dfrac{36}{13}\right)\)
\(=\dfrac{3}{4}.\dfrac{-104}{13}\)
\(=\dfrac{3}{4}.\left(-8\right)\)
\(=-6\)
a,23.54−34.23=23.(54−34)=23.
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=
a,32.45−43.32=32.(45−43)=32.42=31
b,2.(−32)−72=−6.12−7.12=(−6−7).12=−13.12=−132b,2.\left(\dfrac{-3}{2}\right)-\dfrac{7}{2}=-6.\dfrac{1}{2}-7.\dfrac{1}{2}=\left(-6-7\right).\dfrac{1}{2}=-13.\dfrac{1}{2}=\dfrac{-13}{2}b,2.(2−3)−27=−6.21−7.21=(−6−7).21=−13.21=2−13
c,−34.5313−0,75.3613=−34.(6813−3613)=−34.3213=−2413c,-\dfrac{3}{4}.5\dfrac{3}{13}-0,75.\dfrac{36}{13}=-\dfrac{3}{4}.\left(\dfrac{68}{13}-\dfrac{36}{13}\right)=-\dfrac{3}{4}.\dfrac{32}{13}=-\dfrac{24}{13}c,−43.5133−0,75.1336=−43.(
a) \dfrac{2}{3} \cdot \dfrac{5}{4}-\dfrac{3}{4} \cdot \dfrac{2}{3}=\dfrac{2}{3} \cdot\left(\dfrac{5}{4}-\dfrac{3}{4}\right)=\dfrac{2}{3} \cdot \dfrac{1}{2}=\dfrac{1}{3}32⋅45−43⋅32=32⋅(45−43)=32⋅21=31;
b) 2 \cdot\left(\dfrac{-3}{2}\right)^{2}-\dfrac{7}{2}=2 \cdot \dfrac{9}{4}-\dfrac{7}{2}=\dfrac{9}{2}-\dfrac{7}{2}=12⋅(2−3)2−27=2⋅49−27=29−27=1
a) \dfrac{2}{3} \cdot \dfrac{5}{4}-\dfrac{3}{4} \cdot \dfrac{2}{3}=\dfrac{2}{3} \cdot\left(\dfrac{5}{4}-\dfrac{3}{4}\right)=\dfrac{2}{3} \cdot \dfrac{1}{2}=\dfrac{1}{3}32⋅45−43⋅32=32⋅(45−43)=32⋅21=31;
b) 2 \cdot\left(\dfrac{-3}{2}\right)^{2}-\dfrac{7}{2}=2 \cdot \dfrac{9}{4}-\dfrac{7}{2}=\dfrac{9}{2}-\dfrac{7}{2}=12⋅(2−3)2−27=2⋅49−27=29−27=1
2.(−32)2−722.(2−3)2−27a)2/5.5/4-3/4.2/3 b)2.(-3/2)^2-7/2
=2/3.(5/4-3/4) =2.9/4-7/2
=2/3.1/2=1/3 =9/2-7-2=1
c)-3/4.5 3/13-0,75.36/13
=-3/4.68/13-3/4.36/13
=-3.17/3-3.9/13=-51/13-27/13=-6
a) \dfrac{2}{3} \cdot \dfrac{5}{4}-\dfrac{3}{4} \cdot \dfrac{2}{3}=\dfrac{2}{3} \cdot\left(\dfrac{5}{4}-\dfrac{3}{4}\right)=\dfrac{2}{3} \cdot \dfrac{1}{2}=\dfrac{1}{3}32⋅45−43⋅32=32⋅(45−43)=32⋅21=31;
b) 2 \cdot\left(\dfrac{-3}{2}\right)^{2}-\dfrac{7}{2}=2 \cdot \dfrac{9}{4}-\dfrac{7}{2}=\dfrac{9}{2}-\dfrac{7}{2}=12⋅(2−3)2−27=2⋅49−27=29−27=1
a) \(\dfrac{2}{3}\).\(\dfrac{5}{4}\). - \(\dfrac{3}{4}\).\(\dfrac{2}{3}\)
= \(\dfrac{2}{3}\).( \(\dfrac{5}{4}\) - \(\dfrac{3}{4}\) )
= \(\dfrac{2}{3}\).\(\dfrac{2}{4}\)
= \(\dfrac{4}{12}\) = \(\dfrac{1}{3}\)
b) 2. \(\dfrac{-3^2}{2}\) - \(\dfrac{7}{2}\)
= 2.\(\dfrac{9}{4}\) - \(\dfrac{7}{2}\)
= \(\dfrac{18}{4}\) - \(\dfrac{7}{2}\)
= \(\dfrac{4}{4}\) = 1
c) \(-\dfrac{3}{4}\).\(5\dfrac{3}{13}\) - 0,75.\(\dfrac{36}{13}\)
=\(-\dfrac{3}{4}\).\(\dfrac{68}{13}\) - \(\dfrac{3}{4}\).\(\dfrac{36}{13}\)
= -\(\dfrac{3}{4}\).( \(\dfrac{68}{13}\) - \(\dfrac{36}{13}\) )
= \(\dfrac{3}{4}\).\(\dfrac{32}{13}\)
= \(-\dfrac{24}{13}\)
a)2/3 . 5/4 - 3/4 . 2/3
=5/6 - 1/2
= 1/3
b)2.(-3/2)mu 2 - 7/2
=9/2 - 7/2
=1
c)-3/4 . 5va3/13 - 0.75 . 36/13
=-3/4 . 68/13 - 3/4 . 36/13
=-51/13 - 27/13
=-6
) 23.54−34.2332.45−43.32
=23.(54−34)=32.(45−43)
=23.24=32.42
=23.12=32.21
=13=31
b) 2.(−32)2−722.(2−3)2−27
=2.94−72=2.49−
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a) 23⋅54−34⋅23=23⋅(54−34)=23⋅12=1332⋅45−43⋅32=32⋅(45−43)=32⋅21=31;
b) 2⋅(−32)2−72=2⋅94−72=92−72=12⋅(2−3)2−27=2⋅49−27=29−27=1;
c)
a/ 1/3
a/ 1/3
b/-13/2
c/-24/13
1/3
1
-6
File: undefined
a) 23⋅54−34⋅23=23⋅(54−34)=23⋅12=1332⋅45−43⋅32=32⋅(45−43)=32⋅21=31;
b) 2⋅(−32)2−72=2⋅94−72=92−72=12⋅(2−3)2−27=2⋅49−27=29−27=1;
c)
\(\dfrac{2}{3}\times\dfrac{5}{4}-\dfrac{3}{4}\times\dfrac{2}{3}=\dfrac{2}{3}\times(\dfrac{5}{4}-\dfrac{3}{4})=\dfrac{2}{3}\times\dfrac{1}{2}=\dfrac{1}{3}\)
\(2\times(-\dfrac{3}{2})^2-\dfrac{7}{2}=2\times\dfrac{9}{4}-\dfrac{7}{2}=\dfrac{9}{2}-\dfrac{7}{2}=1\)\(\dfrac{3}{4}\times\dfrac{3}{15}-0.75\times\dfrac{36}{13}=\dfrac{3}{4}\times\dfrac{3}{15}-\dfrac{3}{4}\times\dfrac{36}{13}=\dfrac{3}{4}\times(\dfrac{3}{15}-\dfrac{36}{13})=\dfrac{3}{4}\times\dfrac{-167}{65}=\dfrac{-501}{260}\)