\(a.=\dfrac{2019}{2020}\times\left(\dfrac{4}{11}+\dfrac{5}{11}+\dfrac{2}{11}\right)\\ =\dfrac{2019}{2020}\times1=\dfrac{2019}{2020}\\ b.=\dfrac{25}{27}\times\left(\dfrac{17}{14}-\dfrac{1}{14}-\dfrac{2}{14}\right)\\ =\dfrac{25}{27}\times1=\dfrac{25}{27}\)

Thanks mik chữ cũng hơi ẩu

1) \(=\left(\frac{3}{5}+\frac{2}{5}\right).\frac{6}{11}\)

\(=1.\frac{6}{11}\)

\(=\frac{6}{11}\)

2)\(\frac{17}{25}.\left(\frac{11}{19}+\frac{6}{19}+\frac{2}{19}\right)\)

\(=\frac{17}{25}.1\)

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

2.\(\frac{17}{25}.\frac{11}{19}+\frac{17}{25}.\frac{6}{19}+\frac{17}{25}.\frac{2}{19}=\frac{17}{25}\left(\frac{11}{19}+\frac{6}{19}+\frac{2}{19}\right)\\ =\frac{17}{25}.1\\ =\frac{17}{25}\)

a: =>(x-2)^3*[(x-2)^8-1]=0

=>(x-2)(x-3)(x-1)=0

=>\(x\in\left\{2;3;1\right\}\)

b: (x-5)^24=(x-5)^9

=>\(\left(x-5\right)^9\cdot\left[\left(x-5\right)^{15}-1\right]=0\)

=>x-5=0 hoặc x-5=1

=>x=6 hoặc x=5

c: =>(x-5)^4*[(x-5)^21-1]=0

=>x-5=0 hoặc x-5=1

=>x=5 hoặc x=6

a) \(\left(x-2\right)^{11}=\left(x-2\right)^3\)

\(\Rightarrow\left(x-2\right)^{11}-\left(x-2\right)^3=0\)

\(\Rightarrow\left(x-2\right)^3\left[\left(x-2\right)^8-1\right]=0\)

\(\Rightarrow\left[{}\begin{matrix}\left(x-2\right)^3=0\\\left(x-2\right)^8-1=0\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x-2=0\\\left(x-2\right)^8=1\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=2\\x-2=1\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=2\\x=3\end{matrix}\right.\)

b) \(\left(x-5\right)^{24}=\left(x-5\right)^9\)

\(\Rightarrow\left(x-5\right)^{24}-\left(x-5\right)^9=0\)

\(\Rightarrow\left(x-5\right)^9\left[\left(x-5\right)^{15}-1\right]=0\)

\(\Rightarrow\left[{}\begin{matrix}\left(x-5\right)^9=0\\\left(x-5\right)^{15}-1=0\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x-5=0\\\left(x-5\right)^{15}=1\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=5\\x-5=1\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=5\\x=6\end{matrix}\right.\)

c) \(\left(x-5\right)^{25}=\left(x-5\right)^4\)

\(\Rightarrow\left(x-5\right)^{25}-\left(x-5\right)^4\)

\(\Rightarrow\left(x-5\right)^4\left[\left(x-5\right)^{21}-1\right]=0\)

\(\Rightarrow\left[{}\begin{matrix}\left(x-5\right)^4=0\\\left(x-5\right)^{21}-1=0\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x-5=0\\\left(x-5\right)^{21}=1\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=5\\x-5=1\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=5\\x=6\end{matrix}\right.\)

a)2-x=17-(-5)

2-x=17+5

2-x=22

x=2-20

x=-20

b)x-12=-9-15

x-12=-24

x=(-24)+12

x=-12

c)11-(15+11)=x-(25-9)

11-26=x-16

-15=x-16

x=-15+16

x=1

d)x-25=(7-x)-(25+7)

x-25=(7-x)-32

2x-25=7-32

2x-25=-25

2x=(-25)+25

2x=0

x=0:2

x=0

tick cho mk nha bạn

a)2-x=17-(-5)

2-x=17+5

2-x=22

x=2-20

x=-20

b)x-12=-9-15

x-12=-24

x=(-24)+12

x=-12

c)11-(15+11)=x-(25-9)

11-26=x-16

-15=x-16

x=-15+16

x=1

d)x-25=(7-x)-(25+7)

x-25=(7-x)-32

2x-25=7-32

2x-25=-25

2x=(-25)+25

2x=0

x=0:2

x=0

a)2-x=17-(-5)

2-x=17+5

2-x=22

x=2-20

x=-20

b)x-12=-9-15

x-12=-24

x=(-24)+12

x=-12

c)11-(15+11)=x-(25-9)

11-26=x-16

-15=x-16

x=-15+16

x=1

d)x-25=(7-x)-(25+7)

x-25=(7-x)-32

2x-25=7-32

2x-25=-25

2x=(-25)+25

2x=0

x=0:2

x=0

a, 11 - ( 15 + 11 ) = x - ( 25 - 9 )

11-15-11=x-25+9

-15=x-16

x=1

b, 2 - x = 17 - ( - 5 )

2-x=22

x=-20

c, x - 12 = ( - 9 ) - 15

x-12=-24

x=-12

d, 9 - 25 = ( 7 - x ) - ( 25 + 7 )

(7-x)-32=-16

7-x=16

x=-9

#H

\(a,2-x=17-\left(-5\right)\)

\(\Rightarrow2-x=17+5\)

\(\Rightarrow2-x=22\)

\(\Rightarrow x=2-22\)

\(\Rightarrow x=-20\)

Vay...

\(b,11-\left(15+11\right)=x-\left(25-9\right)\)

\(\Rightarrow11-26=x-16\)

\(\Rightarrow-15=x-16\)

\(\Rightarrow-15+16=x\)

\(\Rightarrow x=1\)

\(c,9-25=\left(7-x\right)-\left(25+7\right)\)

\(\Rightarrow-16=7-x-32\)

\(\Rightarrow-16=-x-25\)

\(\Rightarrow x=-25+16\)

\(\Rightarrow x=-9\)

Vay \(x=-9\)

a) \(\dfrac{7}{9}\times\dfrac{13}{25}\times\dfrac{9}{7}=\left(\dfrac{7}{9}\times\dfrac{9}{7}\right)\times\dfrac{13}{25}=1\times\dfrac{13}{25}=\dfrac{13}{25}\)

b) \(\dfrac{5}{9}\times\dfrac{21}{25}+\dfrac{21}{25}\times\dfrac{4}{9}\)

\(=\dfrac{21}{25}\times\left(\dfrac{5}{9}+\dfrac{4}{9}\right)\)

\(=\dfrac{21}{25}\times1=\dfrac{21}{25}\)

c) \(\dfrac{19}{5}\times\dfrac{11}{16}-\dfrac{9}{5}\times\dfrac{11}{16}\)

\(=\dfrac{11}{16}\times\left(\dfrac{19}{5}-\dfrac{9}{5}\right)\)

\(=\dfrac{11}{16}\times2=\dfrac{22}{16}=\dfrac{11}{8}\)