a)

5 7 ⋅ 10 11 + 5 7 ⋅ 14 11 − 5 7 ⋅ 17 11 = 5 7 10 11 + 14 11 − 17 11 = 5 7 .1 = 5 7

b)

1 3 ⋅ 4 5 + 1 3 ⋅ 1 1 5 − − 2 3 1 = 1 3 ⋅ 4 5 + 1 3 ⋅ 6 5 + 2 3 = 1 3 4 5 + 6 5 + 2 3 = 1 3 .2 + 2 3 = 4 3

1334:13 hk trọn bạn ơi

231-(x-6)=1339:13

  231-(x-6)=103

         x-6=231-103

          x-6=128

             x=128+6

             x=134

\(231-\left(x-6\right)=1339:13\)

\(231-\left(x-6\right)=103\)

\(x-6=231-103\)

\(x-6=128\)

\(x=134\)

231 - (x - 6) = 1339 : 13

=> 231 - (x - 6) = 103 

=> x - 6 = 231 - 103 

=> x - 6 = 128

=> x =    128 + 6

=> x =  134 

Vậy x = 134  

#)Giải :

\(231-\left(x-6\right)=1339\div13\)

\(\Leftrightarrow231-\left(x-6\right)=103\)

\(\Leftrightarrow x-6=128\)

\(\Leftrightarrow x=134\)

231 - ( y-6) = 1339 : 13

231 - ( y-6 ) = 103

y - 6 = 231 -103 =128

y = 128 + 6 134

231- (y-6) = 1339 : 13

=> 231 - (y-6) = 103

=> y- 6 = 231 - 103 = 128

=> y = 128 + 6 

=> y = 134  

x là 122 nha bn

k mk nha bn

thanks nhju

231 - ( x - 6 ) = 1339 : 13

231 - ( x - 6 ) = 13

           x - 6   = 231 - 13

           x - 6   = 118

            x        = 118 + 6

            x         = 124

\(231-\left(x-6\right)=1339\div13\)

\(231-\left(x-6\right)=103\)

\(x-6=128\)

\(x=128+6\)

\(x=134\)

Đảm bảo đúng mình học rồi!

231 - ( x - 6 ) = 1339 : 13

231 - x + 6 = 103

231 - x = 103 - 6

231 - x = 97

         x = 231 - 97 

         x = 134

231-(x-6)=1339:13

=>231-(x-6)=103

=>x-6=231-103

=>x-6=128

=>x=128+6

=>x=134

Hk tốt !

\(231-\left(x-6\right)=1339\div9\)

\(\Leftrightarrow231-x+6=103\)

\(\Leftrightarrow237-x=103\)

\(\Leftrightarrow-x=103-237\)

\(-x=-134\)

\(\Leftrightarrow x=134\)

_Minh ngụy_

\(231-\left(x-6\right)=\frac{1339}{13}\)

\(231-\left(x-6\right)=\frac{1339}{13}=103\)

\(=>231-103=x-6\)

\(=>x-6=128\)

\(=>x=128+6=134\)

\(\Leftrightarrow\)231-x+6=103

\(\Leftrightarrow\)231-x=103-6

\(\Leftrightarrow\)x=231-97

\(\Leftrightarrow\)x=134

231-x+6=103

134-x=0

x=134

\(\Leftrightarrow\left(\dfrac{1}{11}-\dfrac{1}{13}+\dfrac{1}{13}-\dfrac{1}{15}+...+\dfrac{1}{19}-\dfrac{1}{21}\right)-x+\dfrac{221}{231}=\dfrac{4}{3}\)

\(\Leftrightarrow\dfrac{10}{231}+\dfrac{221}{231}-x=\dfrac{4}{3}\)

=>1-x=4/3

hay x=-1/3

231-(x-6)=1339:13

231-(x-6) =103

x -6 =  231-103

x-6 = 128

x=128+6

=>x =134

li-ke