a)-(2x + 15 ) + 13 = -234

\(\Leftrightarrow\)-2x-15+13+234=0

\(\Leftrightarrow\)2x=232

\(\Leftrightarrow\)x=116

b)2+4+6+8 +..............+2x=182

\(\Leftrightarrow\)2(1+2+3+4+.....+x) =182

\(\Leftrightarrow\)1+2+3+4+.....+x= 182/2 = 91

\(\Leftrightarrow\)x(x+1)/2 =91

\(\Leftrightarrow\)x(x+1)= 182

\(\Leftrightarrow\)x(x+1) = 13(13+1)

\(\Leftrightarrow\)\(\hept{\begin{cases}x=13\\x+1=13+1\end{cases}}\Leftrightarrow x=13\)

Vậy...

a/ \(x-\dfrac{3}{7}=\dfrac{2}{5}\cdot\dfrac{1}{4}\)

\(x-\dfrac{3}{7}=\dfrac{1}{10}\)

\(x=\dfrac{1}{10}+\dfrac{3}{7}=\dfrac{37}{70}\)

Vậy....

b/ \(x+\dfrac{4}{5}=-\dfrac{5}{12}\cdot\dfrac{3}{25}\)

\(x+\dfrac{4}{5}=-\dfrac{1}{20}\)

\(x=-\dfrac{1}{20}-\dfrac{4}{5}=-\dfrac{17}{20}\)

Vậy....

c/ \(\dfrac{x}{182}=-\dfrac{6}{12}\cdot\dfrac{35}{91}\)

\(\dfrac{x}{182}=-\dfrac{5}{26}\)

\(=>x\cdot26=-5\cdot182\)

\(26x=-910\)

\(x=-910:26=-35\)

Vậy....

a) Ta có: \(x-\dfrac{3}{7}=\dfrac{2}{5}\cdot\dfrac{1}{4}\)

\(\Leftrightarrow x-\dfrac{3}{7}=\dfrac{1}{10}\)

\(\Leftrightarrow x=\dfrac{1}{10}+\dfrac{3}{7}=\dfrac{7}{70}+\dfrac{30}{70}\)

hay \(x=\dfrac{37}{70}\)

Vậy: \(x=\dfrac{37}{70}\)

Trả lời

a)964.3+496.4-496.6

=964.3+[496.(4-6)]

=964.3+(-992)

=2892+(-992)

=1900

b)2019.(2020+1)-2019.2020

=2019.2020.2019-2019.2020

=2019

c)436+324.(234-1)-234.324+324

=436+324.234-324-234.324+324

=436

d)472.(36-1)+35.8

=472.35+35.8

=35.(472+8)

=35.480

=16 800

Ko chắc nha, sai thì cho mk xl vì làm phiền bạn !

b)2019.(2020+1)-2019.2020

=2019.(2020+1-2020)

=2019.1

=2019

1/3(2x-5)=-2/3-3/2=-13/6

2x-5=-13/6:1/3=-13/2

2x=-13/2+5

2x=-3/2

x=-3/2:2=-3/4

       Trương Ứng Hòa

Conan bn sai rùi nhé tại sao chỉ còn 1/3 ? còn (-1/3)chứ

a, \(x\) - \(\dfrac{5}{7}\) = \(\dfrac{1}{9}\) 

    \(x\)        = \(\dfrac{1}{9}\) + \(\dfrac{5}{7}\)

    \(x\)        = \(\dfrac{52}{63}\)

b, \(\dfrac{2x}{5}\) = \(\dfrac{6}{2x+1}\)

     2\(x\).(2\(x\) + 1) = 30

     4\(x^2\)+ 2\(x\)  - 30 = 0

  4\(x^2\) + 12\(x\) - 10\(x\) - 30 = 0

   (4\(x^2\) + 12\(x\)) - (10\(x\) + 30) =0

   4\(x\).(\(x\) + 3) - 10.(\(x\) +3) = 0

        2 (\(x\) + 3).(2\(x\) -  5) = 0

            \(\left[{}\begin{matrix}x+3=0\\2x-5=0\end{matrix}\right.\)

             \(\left[{}\begin{matrix}x=-3\\x=\dfrac{5}{2}\end{matrix}\right.\)

Vậy \(x\) \(\in\) {-3; \(\dfrac{5}{2}\)}

A = 4 . 2 . 25 . 5 . 175 

A = 2² . 2 . 5² . 5 . 5² . 7 

A = 2²⁺¹ . 5²⁺¹⁺² . 7  

A = 2³ . 5⁵ .7

A = 175000

\(B=4^2-10^4:\left(50\cdot273-50\cdot73\right)\)

\(B=4^2-10^4:\left[50\cdot\left(273-73\right)\right]\)

\(B=4^2-10^4:\left(50\cdot200\right)\)

\(B=4^2-10^4:10^4=4^2-1=15\)

\(C=3\times53\times6+2\times9\times87-18\times40\)

\(C=18\times53+18\times87-18\times40\)

\(C=18\times\left(53+87-40\right)\)

\(C=18\times100=1800\)

\(\frac{x}{15}=\frac{3}{5}+\frac{-2}{3}\)

\(\frac{x}{15}=\frac{-1}{15}\)

=> \(x=-1\)

\(\frac{x}{182}=\frac{-6}{14}\cdot\frac{35}{91}\)

\(\frac{x}{182}=\frac{-15}{91}\)

=> \(91x=182\cdot\left(-15\right)\)

=> \(91x=-2730\)

=> \(x=-30\)

g, \(\frac{x}{15}=\frac{3}{5}+\frac{-2}{3}\Leftrightarrow\frac{x}{15}=\frac{3}{5}-\frac{2}{3}\Leftrightarrow\frac{x}{15}=-\frac{1}{15}\)

\(\Leftrightarrow x=-1\)

h, \(\frac{x}{182}=\frac{-6}{14}.\frac{35}{91}\Leftrightarrow\frac{x}{182}=-\frac{15}{91}\Leftrightarrow\frac{x}{182}=\frac{-30}{182}\)

\(\Leftrightarrow x=-30\)