\(1000-345+345:y=655+345:y\)

\(y:2\times5+1234=2234\)

\(\Rightarrow y:2\times5=1000\)

\(\Rightarrow y:2=200\)

\(\Rightarrow y=400\)

a)x*4/5:2=6/7               b)6/5:x:5/4=10/15

x*4/5=6/7 x 2                6/5:x=10/15 x 5/4

x*4/5=12/7                     6/5:x=5/6

x=12/7:4/5                       x=6/5:5/6

x=15/7                            x=36/25

a) x * 4/5 : 2 = 6/7

x * 4/5 = 6/7 *2

x *4/5        = 12/7

x                = 12/7 : 4/5

x               = 15/7

    Vậy x = 15/7

b) 6/5 : x : 5/4 = 10/15

6/5 : x              = 10/15 * 5/4

6/5 :x               =5/6

        x              = 6/5  : 5/6

        x               = 36/25

         Vậy x = 36/25

Ta có :

( x + 2 ) . ( y - 5 ) = - 5 =  5 . ( -1 ) = -5 . 1 

Ta có bảng sau :

\(\orbr{\begin{cases}x+2=-5\\x-5=-5\orbr{\begin{cases}\\\end{cases}}\end{cases}}\)\(\Rightarrow\orbr{\begin{cases}x+2=-5\\x-5=-5\end{cases}}\Rightarrow\orbr{\begin{cases}x=-5-2\\x=-5+5\end{cases}}\Rightarrow\orbr{\begin{cases}x=-7\\x=0\end{cases}}\)

Vậy x=-7và 0

\(\left(x+\dfrac{1}{3}\right)\times\dfrac{9}{14}\times\dfrac{7}{3}-\dfrac{1}{3}=1:\dfrac{9}{5}\\ \Rightarrow\left(x+\dfrac{1}{3}\right)\times\dfrac{3}{2}-\dfrac{1}{3}=\dfrac{5}{9}\\ \Rightarrow\left(x+\dfrac{1}{3}\right)\times\dfrac{3}{2}=\dfrac{5}{9}+\dfrac{1}{3}\\ \Rightarrow\left(x+\dfrac{1}{3}\right)\times\dfrac{3}{2}=\dfrac{8}{9}\\ \Rightarrow x+\dfrac{1}{3}=\dfrac{8}{9}:\dfrac{3}{2}\\ \Rightarrow x+\dfrac{1}{3}=\dfrac{16}{27}\\ \Rightarrow x=\dfrac{16}{27}-\dfrac{1}{3}\\ \Rightarrow x=\dfrac{7}{27}\)

\(\frac{7}{4}-x+\frac{4}{3}=\frac{5}{19}\)

\(\Rightarrow\frac{7}{4}-x=\frac{5}{19}-\frac{4}{3}\)

\(\Rightarrow\frac{7}{4}-x=-\frac{61}{57}\)

\(\Rightarrow x=\frac{7}{4}+\frac{61}{57}\)

\(\Rightarrow x=???\)

tíc mình nha

,làm ơn giúp mik với ah

\(\left(1+\dfrac{2}{3}\right).\left(1+\dfrac{2}{4}\right).\left(1+\dfrac{2}{5}\right)....\left(1+\dfrac{2}{2020}\right).\left(1+\dfrac{2}{2021}\right)\)

= \(\dfrac{5}{3}.\dfrac{6}{4}.\dfrac{7}{5}.\dfrac{8}{6}.\dfrac{9}{7}....\dfrac{2022}{2020}.\dfrac{2023}{2021}\)

= \(\dfrac{1}{3}.\dfrac{1}{4}.2022.2023\)

= \(\dfrac{337.2023}{2}\)

= \(\dfrac{\text{681751}}{2}\)

Bài 1:

a, 2x + 35 = x - 27

    2x - x = -27 - 35

    x = -62

 b, 2x - 41 = 3x + (-23)

     2x - 3x = -23 + 41

     -x = 18

     x = -18

c, 4 . (x - 3) - 3 . (x - 5) = 45 . (-2) - 34

   4x - 12 - 3x + 15 = -90 - 34

   4x - 3x = -90 - 34 + 12 - 15

   x = -127

Bài 2:

- ( -1234 + 345 - 29 ) - ( 1234 + 135 - 59 )

= 1234 - 345 + 29 - 1234 - 135 + 59

= (1234 - 1234) - (345 + 135) + (29 + 59)

= 0 - 480 + 88

= -392

a)2x+35=x-27

2x-x=-27-35

1x=-62

x=-62:1

X=-62

1, a, 2x + 35 = x - 27 

<=> 2x - x = -27 - 35 

,<=> x = -72 

Vậy x = -72

b, 2x - 41 = 3x + ( - 23 )

<=> 2x - 3x = 41 - 23

<=> -1x = 18

<=> x = -18 

Vậy x = -18 

c, tương tự dùng phân phối .

2, = 1234 - 345 + 29 - 1234 - 135 + 59 

= ( 1234 - 1234 ) + ( -345 - 135 ) + ( 29 + 59 )

= 0 - 480 + 88 = -480 + 88 = -392

\(4\left(x-1\right)-3\left(x-2\right)=-5\)

\(\Leftrightarrow4x-4-3x+6=-5\)

\(\Leftrightarrow x=-5+4-6\)

\(\Leftrightarrow x=-7\)

Vậy x=-7

Ta có: 4(x-1) - 3(x-2) = -5

          (4x-4) - (3x-6) = -5

          4x - 4 - 3x + 6 = -5 

     (4x - 3x) + (-4+6) = -5

                       x + 2  = -5

                             x  = -5 - 2

                              x = -7

                         Vậy x = -7

mk cx ko biết nhưng thường mk làm là x - 1

còn 1 - x thì có một trường hợp là x = 0