D

D

`@` `\text {Ans}`

`\downarrow`

`a.`

\(0,3-\dfrac{4}{9}\div\dfrac{4}{3}\cdot\dfrac{6}{5}+1\)

`=`\(0,3-\dfrac{1}{3}\cdot\dfrac{6}{5}+1\)

`=`\(0,3-0,4+1\)

`= -0,1 + 1`

`= 0,9`

`b.`

\(1+2\div\left(\dfrac{2}{3}-\dfrac{1}{6}\right)\cdot\left(-2,25\right)\)

`=`\(1+2\div\dfrac{1}{2}\cdot\left(-2,25\right)\)

`=`\(1+4\cdot\left(-2,25\right)\)

`= 1+ (-9) = -8`

`c.`

\(\left[\left(\dfrac{1}{4}-0,5\right)\cdot2+\dfrac{8}{3}\right]\div2\)

`=`\(\left(-\dfrac{1}{4}\cdot2+\dfrac{8}{3}\right)\div2\)

`=`\(\left(-\dfrac{1}{2}+\dfrac{8}{3}\right)\div2\)

`=`\(\dfrac{13}{6}\div2\)

`=`\(\dfrac{13}{12}\)

`d.`

\(\left[\left(\dfrac{3}{8}-\dfrac{5}{12}\right)\cdot6+\dfrac{1}{3}\right]\cdot4\)

`=`\(\left(-\dfrac{1}{24}\cdot6+\dfrac{1}{3}\right)\cdot4\)

`=`\(\left(-\dfrac{1}{4}+\dfrac{1}{3}\right)\cdot4\)

`=`\(\dfrac{1}{12}\cdot4=\dfrac{1}{3}\)

`e.`

\(\left(\dfrac{4}{5}-1\right)\div\dfrac{3}{5}-\dfrac{2}{3}\cdot0,5\)

`=`\(-\dfrac{1}{5}\div\dfrac{3}{5}-\dfrac{1}{3}\)

`=`\(-\dfrac{1}{3}-\dfrac{1}{3}=-\dfrac{2}{3}\)

`f.`

\(0,8\div\left\{0,2-7\left[\dfrac{1}{6}+\left(\dfrac{5}{21}-\dfrac{5}{14}\right)\right]\right\}\)

`=`\(0,8\div\left[0,2-7\left(\dfrac{1}{6}-\dfrac{5}{42}\right)\right]\)

`=`\(0,8\div\left(0,2-7\cdot\dfrac{1}{21}\right)\)

`=`\(0,8\div\left(0,2-\dfrac{1}{3}\right)\)

`= 0,8 \div (-2/15)`

`=-6`

`@` `yHGiangg.`

a) Ta có: \(\dfrac{-5}{7}\left(\dfrac{14}{5}-\dfrac{7}{10}\right):\left|-\dfrac{2}{3}\right|-\dfrac{3}{4}\left(\dfrac{8}{9}+\dfrac{16}{3}\right)+\dfrac{10}{3}\left(\dfrac{1}{3}+\dfrac{1}{5}\right)\)

\(=\dfrac{-5}{7}\cdot\dfrac{3}{2}\cdot\dfrac{21}{10}-\dfrac{3}{4}\cdot\dfrac{56}{3}+\dfrac{10}{3}\cdot\dfrac{8}{15}\)

\(=\dfrac{-9}{4}-14+\dfrac{16}{9}\)

\(=\dfrac{-1621}{126}\)

b) Ta có: \(\dfrac{17}{-26}\cdot\left(\dfrac{1}{6}-\dfrac{5}{3}\right):\dfrac{17}{13}-\dfrac{20}{3}\left(\dfrac{2}{5}-\dfrac{1}{4}\right)+\dfrac{2}{3}\left(\dfrac{6}{5}-\dfrac{9}{2}\right)\)

\(=\dfrac{-17}{26}\cdot\dfrac{13}{17}\cdot\dfrac{-3}{2}-\dfrac{20}{3}\cdot\dfrac{3}{20}+\dfrac{2}{3}\cdot\dfrac{-33}{10}\)

\(=\dfrac{3}{4}-1-\dfrac{11}{5}\)

\(=-\dfrac{49}{20}\)

a) (- 15) . 4 – 240 : 6 + 36 : (- 2) . 3 = - 60 – 40 + (- 18) = - 118

b) (- 2)⁵ + [(- 69) : 3 + 53] . (- 2) – 8 

= - 32 + (- 23 + 53) . (- 2) - 8

= - 32 + 30 . (- 2) - 8

= - 32 + (- 60) – 8

= - 100

a)\(=\dfrac{3}{3}+\dfrac{4}{3}=\dfrac{7}{3}\)

b)\(=\dfrac{5}{9}\times\dfrac{3}{2}=\dfrac{15}{18}=\dfrac{5}{6}\)

d)\(=\left(\dfrac{12}{8}-\dfrac{3}{8}\right)\times2=\dfrac{9}{8}\times2=\dfrac{18}{8}=\dfrac{9}{4}\)

c)\(=\dfrac{4}{3}-\dfrac{5}{6}=\dfrac{8}{6}-\dfrac{5}{6}=\dfrac{3}{6}=\dfrac{1}{2}\)

a) 1 + 4/3 = 7/3

b) 5/9 : 2/3 = 5/6

c ) 4/3 -1/3 x 5/2

= 1 x 5/2

= 5/2

d) ( 3/2 - 3/8) : 1/2

= 9/8 : 1/2

= 9/4

e) 15/16 : 3/8 x 3/4 

= 5/2 x 3/4

= 15/8

f) 7/19 x 1/3 x 7/19 x 2/3

= 7/19 x (1/3 x 2/3)

= 7/19 x 2/9

= 14/171

g) 3/5 x 8/27 x 25/3

= 3/5 x 25/3 x 8/27 

= 5 x 8/27

= 40/27

h) 1/5 + 4/11 + 4/5 + 7/11

= (1/5 + 4/5) + (4/11 + 7/11)

= 1 + 1

= 2

a) $\frac{3}{2} \times \frac{5}{8} + \frac{7}{4} = \frac{{15}}{{16}} + \frac{7}{4} = \frac{{15}}{{16}} + \frac{{28}}{{16}} = \frac{{43}}{{16}}$

b) $\frac{8}{5}:\left( {\frac{4}{3} - \frac{5}{6}} \right) = \frac{8}{5}:\left( {\frac{8}{6} - \frac{5}{6}} \right) = \frac{8}{5}:\frac{1}{2} = \frac{8}{5} \times 2 = \frac{{16}}{5}$

c) $\frac{3}{4} \times \frac{1}{5} - \frac{1}{{10}} = \frac{3}{{20}} - \frac{1}{{10}} = \frac{3}{{20}} - \frac{2}{{20}} = \frac{1}{{20}}$

a: \(=\dfrac{2^{10}\cdot3^8-2^{10}\cdot3^9}{2^{10}\cdot3^8+2^{10}\cdot3^8\cdot5}=\dfrac{2^{10}\cdot3^8\left(1-3\right)}{2^{10}\cdot3^8\left(1+5\right)}=\dfrac{-2}{6}=\dfrac{-1}{3}\)

b: \(=\dfrac{5^{16}\cdot3^{21}}{5^{15}\cdot3^{22}}=\dfrac{5}{3}\)

\(a,8.\left(\dfrac{-9}{12}\right)=\dfrac{8.\left(-9\right)}{12}=\dfrac{-72}{12}=-6\\ b,\left(\dfrac{-14}{5}\right).\left(-10\right)=\dfrac{\left(-14\right).\left(-10\right)}{5}=\dfrac{140}{5}=28\\ c,9.\left(\dfrac{4}{-3}\right)=\dfrac{9.\left(-4\right)}{3}=\dfrac{-36}{3}=-12\\ d,-15.\left(\dfrac{-5}{6}\right)=\dfrac{\left(-15\right).\left(-5\right)}{6}=\dfrac{75}{6}\\ e,13.\left(\dfrac{-2}{7}\right)=\dfrac{13.\left(-2\right)}{7}=\dfrac{-26}{7}\\ f,\dfrac{7}{26}.\left(-13\right)=\dfrac{7.\left(-13\right)}{26}=\dfrac{-91}{26}\)

a, 8.( -9/12 )=-6

b, ( -14/5 ) . (-10)=28

c, 9. ( 4/-3 )=-12

d, -15. ( -5/6 )=25/2

e, 13. ( -2/7 )-36/7

f, 7/26. ( -13 )=-7/2

\(\text{A = 1-2-3-4+5-6-7-8+9-10-11-12+...........+97-98-99-100}\)

\(\text{A =(1-2-3-4)+(5-6-7-8)+(9-10-11-12)+.............+(97-98-99-100)}\)

\(\text{A =-8+(-16)+(-24)+..................+(-200)}\)

\(\text{A =-8.(1+2+3+......+25)}\)

\(\text{A =-8.[(25-1):1+1.26:2]}\)

\(\text{A =-8.325}\)

\(\text{A =-2600 Vậy A = -2600 }\)

=1+(2-3-4+5)+(6-7-8+9)+...+(98-99-100+101)+102
=1+0+0+0+....+102
=103

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