1) Ta có: \(\left(-\dfrac{2}{3}\right)^2\cdot\dfrac{-9}{8}-25\%\cdot\dfrac{-16}{5}\)

\(=\dfrac{4}{9}\cdot\dfrac{-9}{8}-\dfrac{1}{4}\cdot\dfrac{-16}{5}\)

\(=\dfrac{-1}{2}+\dfrac{4}{5}\)

\(=\dfrac{-5}{10}+\dfrac{8}{10}=\dfrac{3}{10}\)

2) Ta có: \(-1\dfrac{2}{5}\cdot75\%+\dfrac{-7}{5}\cdot25\%\)

\(=\dfrac{-7}{5}\cdot\dfrac{3}{4}+\dfrac{-7}{5}\cdot\dfrac{1}{4}\)

\(=\dfrac{-7}{5}\left(\dfrac{3}{4}+\dfrac{1}{4}\right)=-\dfrac{7}{5}\)

3) Ta có: \(-2\dfrac{3}{7}\cdot\left(-125\%\right)+\dfrac{-17}{7}\cdot25\%\)

\(=\dfrac{-17}{7}\cdot\dfrac{-5}{4}+\dfrac{-17}{7}\cdot\dfrac{1}{4}\)

\(=\dfrac{-17}{7}\cdot\left(\dfrac{-5}{4}+\dfrac{1}{4}\right)\)

\(=\dfrac{17}{7}\)

4) Ta có: \(\left(-2\right)^3\cdot\left(\dfrac{3}{4}\cdot0.25\right):\left(2\dfrac{1}{4}-1\dfrac{1}{6}\right)\)

\(=\left(-8\right)\cdot\left(\dfrac{3}{4}\cdot\dfrac{1}{4}\right):\left(\dfrac{9}{4}-\dfrac{7}{6}\right)\)

\(=\left(-8\right)\cdot\dfrac{3}{16}:\dfrac{54-28}{24}\)

\(=\dfrac{-3}{2}\cdot\dfrac{24}{26}\)

\(=\dfrac{-72}{52}=\dfrac{-18}{13}\)

`1, -2/9 xx 15/17 + (-2/9) xx 2/17`

`= -2/9 xx (15/17 + 2/17)`

`= -2/9 xx 17/17`

`=-2/9xx1`

`=-2/9`

__

`-5/3 xx 6/5 + (-7/9) xx 3/10`

`= -30/15 + (-21/90)`

`= -2 + (-7/30)`

`=-60/30 +(-7/30)`

`=-67/30`

__

`15/20 xx 7/5 + (-9/7) xx (-6/4)`

`=3/4 xx7/5 + (-9/7) xx(-6/4)`

`= 21/20 + 54/28`

`= 21/20 + 27/14`

`=417/140`

__

`-25/13 xx 5/19 + (-25/13) xx 14/19`

`=-25/13 xx (5/19 +14/19)`

`=-25/13 xx 19/19`

`= -25/13 xx 1`

`=-25/13`

__

`-7/13 xx 13/5 + (-9/7) xx 5/3`

`=-7/5 +(-15/7)`

`=-124/35`

tìm x biết:

(3x-1) [- 1/2x+5]=0

1/4+1/3:(2x-1)=-5

[2x+3/5]² - 9/25=0

-5(x+1/5)-1/2(x-2/3)=3/2x - 5 /6

[x+1/2]x [2/3-2x]=0

17/2-|2x-3/4|=-7/4

2/3x-1/2x =5/12

(x+1/5)²+17/25=26/25

[x.44/7+3/7].11/5-3/7=-2

3[3x-1/2]+1/9=0

Toán lớp 6Tìm x

 Trả lời  Câu hỏi tương tự

Chưa có ai trả lời câu hỏi này,bạn hãy là người đâu tiên giúp nguyenvanhoang giải bài toán này !

3(3x-1/2)^3+1/9=0

Ta có: \(-\frac35\cdot\frac27-\frac35\cdot\frac57\)

\(=-\frac35\left(\frac27+\frac57\right)\)

\(=-\frac35\cdot\frac77=-\frac35\)

\(\frac{22}{25}\times\frac{5}{11}-\frac{33}{25}:\frac{11}{5}+\frac{58}{11}\)

\(=\frac{22}{25}\times\frac{5}{11}-\frac{33}{25}\times\frac{5}{11}+\frac{58}{11}\)

\(=\frac{5}{11}\times\left(\frac{22}{25}+\frac{33}{25}\right)+\frac{58}{11}\)

\(=\frac{5}{11}\times\frac{11}{5}+\frac{58}{11}\)

\(=1+\frac{58}{11}\)

\(=\frac{11}{11}+\frac{58}{11}\)

\(=\frac{69}{11}\)

\(8\frac{3}{11}-\left(3\frac{5}{7}-7\frac{8}{11}\right)\)

\(=\frac{91}{11}-\left(\frac{26}{7}-\frac{85}{11}\right)\)

\(=\frac{91}{11}-\frac{26}{7}+\frac{85}{11}\)

\(=\frac{91}{11}+\frac{85}{11}-\frac{26}{7}\)

\(=16-\frac{26}{7}\)

\(=\frac{86}{7}\)

\(\frac{5}{6}x+325\%=\frac{3}{2}x-30,75\)

\(=>\frac{5}{6}x+3,25=\frac{3}{2}x-30,75\)

\(=>\frac{5}{6}x-\frac{3}{2}x=-30,75-3,25\)

\(=>\frac{-2}{3}x=-34\)

\(=>x=-34:\left(-\frac{2}{3}\right)\)

\(=>x=-34.\left(\frac{3}{-2}\right)\)

\(=>x=51\)

1,

\(\dfrac{6}{7}\) + \(\dfrac{-5}{8}\) : (-5) -\(\dfrac{3}{16}\) . \(\left(-2\right)^2\)

= \(\dfrac{6}{7}\) + \(\dfrac{-5}{8}\) . \(\dfrac{-1}{5}\) - \(\dfrac{3}{16}\) . 4

= \(\dfrac{6}{7}\) + \(\dfrac{1}{8}\) - \(\dfrac{3}{4}\)

= \(\dfrac{48}{56}\) + \(\dfrac{7}{56}\) - \(\dfrac{42}{56}\)

= \(\dfrac{13}{56}\)

3,

a,\(\dfrac{3}{5}\)x - \(\dfrac{7}{10}\)x = \(\dfrac{-1}{2}\)

x.(\(\dfrac{3}{5}\) - \(\dfrac{7}{10}\)) = \(\dfrac{-1}{2}\)

x.\(\dfrac{-1}{10}\)= \(\dfrac{-1}{2}\)

x =\(\dfrac{-1}{2}\):\(\dfrac{-1}{10}\)

x = 5

c, (2,5x - 3,6) : \(\dfrac{15}{7}\) = -1

( \(\dfrac{5}{2}\)x - \(\dfrac{18}{5}\)) : \(\dfrac{15}{7}\) = -1

\(\dfrac{5}{2}\)x - \(\dfrac{18}{5}\) = -1 . \(\dfrac{15}{7}\)

\(\dfrac{5}{2}\)x - \(\dfrac{18}{5}\) = \(\dfrac{-15}{7}\)

\(\dfrac{5}{2}\)x = \(\dfrac{-15}{7}\) + \(\dfrac{18}{5}\)

\(\dfrac{5}{2}\)x = \(\dfrac{51}{35}\)

x =\(\dfrac{51}{35}\) : \(\dfrac{5}{2}\)

x = \(\dfrac{102}{175}\)

Mình không biết có chỗ nào sai không nữa.

1:

a: =7/5(40+1/4-25-1/4)-1/2021

=21-1/2021=42440/2021

b: =5/9*9-1*16/25=5-16/25=109/25