A.\(=\frac{17}{25}\times\left(\frac{13}{19}+\frac{6}{19}\right)\)

\(=\frac{17}{25}\times1\)

\(=\frac{17}{25}\)

B\(=\frac{47}{19}:\left(\frac{15}{32}-\frac{15}{17}\right)\)

\(=\frac{47}{19}:1\)

\(=\frac{47}{19}\)

a: =17/25(13/19+6/19)=17/25

b: \(=\dfrac{47}{19}\cdot\dfrac{32}{15}-\dfrac{47}{19}\cdot\dfrac{17}{15}=\dfrac{47}{19}\)

`17/25xx(13/19+6/19)`

`17/25xx1`

`17/25`

`a)17/25xx13/19+17/25xx6/19`

`=17/25xx(13/19+6/19)`

`=17/25xx19/19=17/25`

`b)47/19:15/32-47/19:15/17`

`=47/19xx32/15-47/19xx17/15`

`=47/19xx(32/15-17/15)`

`=47/19xx15/15=47/19`

\(a,\dfrac{-15}{17}=-1+\dfrac{2}{17}\\ -\dfrac{19}{21}=-1+\dfrac{2}{21}\\ Vì:\dfrac{2}{17}>\dfrac{2}{21}\Rightarrow-1+\dfrac{2}{17}>-1+\dfrac{2}{21}\Rightarrow-\dfrac{15}{17}>-\dfrac{19}{21}\\ b,-\dfrac{24}{35}=-1+\dfrac{11}{35};-\dfrac{19}{30}=-1+\dfrac{11}{30}\\ Vì:\dfrac{11}{35}< \dfrac{11}{30}\Rightarrow-1+\dfrac{11}{35}< -1+\dfrac{11}{30}\\ \Rightarrow-\dfrac{24}{35}< -\dfrac{19}{30}\)

Lời giải:
PT \(\Leftrightarrow (\frac{x+1}{11}-1)-(\frac{2x-5}{15}-1)=(\frac{3x-47}{17}+1)-(\frac{4x-59}{19}+1)\)

\(\Leftrightarrow \frac{x-10}{11}-\frac{2(x-10)}{15}=\frac{3(x-10)}{17}-\frac{4(x-10)}{19}\)

\(\Leftrightarrow (x-10)(\frac{1}{11}+\frac{4}{19}-\frac{2}{15}-\frac{3}{17})=0\)

\(\Leftrightarrow x-10=0\Leftrightarrow x=10\)

mẫu phân số thứ 3 bị gì thế

\(\dfrac{x+1}{11}-\dfrac{2x-5}{15}=\dfrac{3x-47}{17}-\dfrac{4x-59}{19}\)

\(\Leftrightarrow\left(\dfrac{x+1}{11}-1\right)-\left(\dfrac{2x-5}{15}-1\right)=\left(\dfrac{3x-47}{17}+1\right)-\left(\dfrac{4x-59}{19}+1\right)\)

\(\Leftrightarrow\dfrac{x-10}{11}-\dfrac{2\left(x-10\right)}{15}=\dfrac{3\left(x-10\right)}{17}-\dfrac{4\left(x-10\right)}{19}\)

\(\Leftrightarrow\dfrac{x-10}{11}-\dfrac{2\left(x-10\right)}{15}-\dfrac{3\left(x-10\right)}{17}+\dfrac{4\left(x-10\right)}{19}=0\)

\(\Leftrightarrow\left(x-10\right)\left(\dfrac{1}{11}-\dfrac{1}{15}-\dfrac{1}{17}+\dfrac{1}{19}\right)=0\)

\(\Leftrightarrow x-10=0\)

\(\Leftrightarrow x=10\)

Vậy x = 10

a)P=\(\dfrac{-2}{7}+\dfrac{14}{29}+\dfrac{12}{33}+\dfrac{15}{29}+\dfrac{21}{33}+\dfrac{2}{7}\)

      =\(\left(\dfrac{-2}{7}+\dfrac{2}{7}\right)+\left(\dfrac{14}{29}+\dfrac{15}{29}\right)+\left(\dfrac{12}{33}+\dfrac{21}{33}\right)\)

      =0+1+1=2

b)\(\dfrac{2}{7}.\dfrac{5}{19}+\dfrac{2}{7}.\dfrac{14}{19}+\dfrac{21}{19}-\dfrac{2}{7}.\dfrac{1}{5}\)

=\(\dfrac{2}{7}.\left(\dfrac{5}{19}+\dfrac{14}{19}-\dfrac{1}{5}\right)+\dfrac{21}{19}\)

=\(\dfrac{2}{7}.\dfrac{4}{5}+\dfrac{21}{19}=\dfrac{887}{665}\)

9: \(=\dfrac{47}{51}\cdot\dfrac{17}{94}-\dfrac{47}{51}\cdot\dfrac{53}{91}-\dfrac{53}{91}\cdot\dfrac{91}{53}+\dfrac{53}{91}\cdot\dfrac{47}{51}\)

\(=\dfrac{1}{6}-1=-\dfrac{5}{6}\)

10: \(=\dfrac{13}{19}\cdot\dfrac{19}{26}-\dfrac{13}{19}\cdot\dfrac{71}{43}+\dfrac{71}{43}\cdot\dfrac{13}{19}-\dfrac{71}{43}\cdot\dfrac{86}{71}\)

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

1: \(=\dfrac{15}{37}\cdot\dfrac{38}{41}-\dfrac{15}{37}\cdot\dfrac{74}{45}-\dfrac{38}{41}\cdot\dfrac{15}{37}-\dfrac{38}{41}\cdot\dfrac{82}{76}\)

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

2: \(=\dfrac{47}{53}\cdot\dfrac{17}{3}-\dfrac{47}{53}\cdot\dfrac{53}{47}+\dfrac{17}{3}\cdot\dfrac{6}{17}-\dfrac{17}{3}\cdot\dfrac{47}{53}\)

\(=-1+2=1\)

\(a,\dfrac{3}{5}+\dfrac{1}{5}.\dfrac{-17}{9}=\dfrac{3}{5}-\dfrac{17}{45}=\dfrac{27}{45}-\dfrac{17}{45}=\dfrac{10}{45}=\dfrac{2}{9}\\ b,\left(-\dfrac{4}{15}-\dfrac{18}{19}\right)-\left(\dfrac{20}{19}+\dfrac{11}{15}\right)=-\dfrac{4}{15}-\dfrac{18}{19}-\dfrac{20}{19}-\dfrac{11}{15}=\left(-\dfrac{4}{15}-\dfrac{11}{15}\right)-\left(\dfrac{18}{19}+\dfrac{20}{19}\right)=-1-2=-3\)

\(a,=\dfrac{3}{5}+\left(-\dfrac{17}{45}\right)=\dfrac{2}{9}\)

\(b,=-\dfrac{4}{15}-\dfrac{18}{19}-\dfrac{20}{19}-\dfrac{11}{15}=-3\)

a. 3/5+1/5.-17/9

=3/5+-17/45

=27/45+-17/45

=2/9

b. (-4/15-18/19)-(20/19+11/15)

=-4/15-18/19-20/19-11/15

=(-4/15-11/15)-(18/19-20/19)

=(-1)-(-2/19)

=(-19/19)-(-2/19)

=-17/19