\(B=\dfrac{-1}{4}+\dfrac{7}{33}-\dfrac{5}{3}-(\dfrac{-15}{12}+\dfrac{6}{11}-\dfrac{68}{49})\)

\(B=\dfrac{-1}{4}+\dfrac{7}{33}-\dfrac{5}{3}+\dfrac{15}{12}-\dfrac{6}{11}+\dfrac{68}{49}\)

\(B=(\dfrac{-1}{4}-\dfrac{5}{3}+\dfrac{15}{12})+(\dfrac{7}{33}-\dfrac{6}{11})+\dfrac{68}{49}\)

\(B=\dfrac{-3-20+15}{12}+\dfrac{7-18}{33}+\dfrac{68}{49}\)

\(B=\dfrac{-8}{12}+\dfrac{-11}{33}+\dfrac{68}{49}\)

\(B=\dfrac{-2}{3}+\dfrac{-1}{3}+\dfrac{68}{49}\)

\(B=-1+\dfrac{68}{49}=\dfrac{-49}{49}+\dfrac{68}{49}=\dfrac{19}{49}\)

gấp ặ 

\(A=7+(\dfrac{7}{12}-\dfrac{1}{2}+3)-(\dfrac{1}{12}+5)\)

\(A=\dfrac{84}{12}+\dfrac{7-6+36}{12}-\dfrac{1+60}{12}\)

\(A=\dfrac{84+7-6+36-1-60}{12}=\dfrac{60}{12}=5\)

 = 7 + ( \(\dfrac{7}{12}\) - \(\dfrac{1}{2}\) + 3) - ( \(\dfrac{1}{12}\)+5)

=  7 + \(\dfrac{7}{12}\) - \(\dfrac{1}{2}\) + 3 - \(\dfrac{1}{12}\) -  5

= 5 + \(\dfrac{6}{12}\) - \(\dfrac{1}{2}\)

= 5 + \(\dfrac{1}{2}\) - \(\dfrac{1}{2}\)

= 5

(0,25)¹³² =  (\(\dfrac{1}{4}\))¹³² = 4^-132

(0,5)³⁰ = ( \(\dfrac{1}{2}\))³⁰ = 2^-30 = (2²)^-15 = 4^-15

8⁷⁰ = (2³)⁷⁰ = (2³)^2.35 = (2²)¹⁰⁵ = 4¹⁰⁵

- \(\dfrac{37}{47}\) = \(\dfrac{10}{47}\) - 1> \(\dfrac{10}{66}\) - 1 = - \(\dfrac{56}{66}\)

vậy -  \(\dfrac{37}{47}\)> - \(\dfrac{56}{66}\)

\(\dfrac{-29}{38}\) = \(\dfrac{9}{38}\) - 1 < \(\dfrac{9}{22}\) - 1 = \(\dfrac{-13}{22}\)

vậy \(\dfrac{-29}{38}\) < \(\dfrac{-13}{22}\)

`19/18 =19/18 - 1 = 1/18`

`2005/2004 = 2005/2004 - 1 = 1/2004`

Mà : `1/18 > 1/2004`

`=> 19/18 > 2005/2004`

\(\dfrac{19}{18}\) = 1 + \(\dfrac{1}{18}\)> 1 + \(\dfrac{1}{2004}\)= \(\dfrac{2005}{2004}\)

\(\dfrac{19}{18}\)  > \(\dfrac{2005}{2004}\)

- \(\dfrac{1}{12}\) - ( 2 \(\dfrac{5}{8}\) - \(\dfrac{1}{3}\))

= - \(\dfrac{1}{12}\) - ( \(\dfrac{21}{8}\) - \(\dfrac{1}{3}\))

= - \(\dfrac{1}{12}\) - ( \(\dfrac{63}{24}\)  - \(\dfrac{8}{24}\))

= - \(\dfrac{1}{12}\) - \(\dfrac{55}{24}\)

= - \(\dfrac{2}{24}\) - \(\dfrac{55}{24}\)

= - \(\dfrac{57}{24}\)

= - \(\dfrac{19}{8}\)

`(-1)/12 - (2 5/8 - 1/3)`

`=(-1)/12 - ( 21/8 - 1/2)`

`=(-1)/12 - (63/24 - 8/12)`

`=(-1)/12 -55/24`

`=(-2)/24 - 55/24`

`=(-2-55)/24`

`=(-57)/24`

`=(-19)/8`

= -3/5 - 3/4 + 3/4 - 2/5 = -3/5 -2/5 = -5/5 = -1