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31 tháng 10 2020

\(a,\frac{1}{3}x+0.25=\frac{5}{7}\)

\(\Leftrightarrow\frac{1}{3}x=\frac{13}{28}\)

\(\Leftrightarrow x=\frac{39}{28}\)

vậy...

\(b,\frac{11}{12}x+0,25=\frac{5}{6}\)

\(\Leftrightarrow\frac{11}{12}x=\frac{7}{12}\)

\(\Leftrightarrow x=\frac{7}{11}\)

vậy.....

\(c,\left(\frac{-1}{3}\right)^2+\frac{2}{3}x=\frac{1}{4}\)

\(\Leftrightarrow\frac{1}{9}+\frac{2}{3}x=\frac{1}{4}\)

\(\Leftrightarrow\frac{2}{3}x=\frac{5}{36}\)

\(\Leftrightarrow x=\frac{5}{24}\)

vậy......

\(d,\left(3x+2\right)^3=-\frac{8}{125}\)

\(\Leftrightarrow3x+2=-\frac{2}{5}\)

\(\Leftrightarrow3x=-\frac{12}{5}\)

\(\Leftrightarrow x=-\frac{4}{5}\)

vậy.......

31 tháng 10 2020

\(\frac{1}{3x}+0,25=\frac{5}{7}\)

\(\frac{1}{3x}+\frac{1}{4}=\frac{5}{7}\)

\(\frac{1}{3x}=\frac{13}{28}\)

\(3x=\frac{28}{13}\)

\(x=\frac{28}{39}\)

\(\frac{11}{12x}+0,25=\frac{5}{6}\)

\(\frac{11}{12x}+\frac{1}{4}=\frac{5}{6}\)

\(\frac{11}{12x}=\frac{7}{12}\)

\(x=\frac{11}{12}:\frac{7}{12}\)

\(x=\frac{7}{11}\)

\(\left(-\frac{1}{3}\right)^2+\frac{2}{3x}=\frac{1}{4}\)

\(\frac{1}{9}+\frac{2}{3x}=\frac{1}{4}\)

\(\frac{2}{3x}=\frac{5}{36}\)

\(x=\frac{2}{3}:\frac{5}{36}\)

\(x=\frac{5}{24}\)

\(\left(3x+2\right)^3=\left(-\frac{8}{125}\right)\)

\(\left(3x+2\right)^3=\left(-\frac{2}{5}\right)^3\)

\(\Rightarrow3x+2=-\frac{2}{3}\)

\(3x=-\frac{8}{3}\)

\(x=-\frac{9}{8}\)

11 tháng 7 2017

1) \(\left|4-2x\right|.\dfrac{1}{3}=\dfrac{1}{3}\)

\(\left|4-2x\right|=\dfrac{1}{3}:\dfrac{1}{3}\)

\(\left|4-2x\right|=\dfrac{1}{3}.3\)

\(\left|4-2x\right|=1\)

=>\(4-2x=\pm1\)

+)\(TH1:4-2x=1\) +)\(TH2:4-2x=-1\)

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

\(2x=3\) \(2x=4+1\)

\(x=3:2\) \(2x=5\)

\(x=1,5\) \(x=5:2\)

Vậy x=1,5 \(x=2,5\)

Vậy x=2,5

11 tháng 7 2017

2) \(\left(-3\right)^2:\left|x+\left(-1\right)\right|=-3\)

\(9:\left|x+\left(-1\right)\right|=-3\)

\(\left|x+\left(-1\right)\right|=9:\left(-3\right)\)

\(\left|x+\left(-1\right)\right|=-3\)

=> \(x+\left(-1\right)\) sẽ không có giá trị nào ( Vì giá trị tuyệt đối luôn luôn lớn hơn hoặc bằng 0 )

Vậy x = \(\varnothing\)

15 tháng 11 2021
|2x-1|+1=4
11 tháng 10 2021

a) \(3\dfrac{4}{5}:\dfrac{8}{5}=0,25:x\)

\(\Rightarrow\dfrac{19}{5}.\dfrac{5}{8}=\dfrac{x}{4}\)

\(\Rightarrow\dfrac{x}{4}=2\Rightarrow x=8\)

b) \(2x+\dfrac{3}{24}=3x-\dfrac{1}{32}\)

\(\Rightarrow x=\dfrac{1}{8}+\dfrac{1}{32}=\dfrac{5}{32}\)

c) \(\dfrac{13x-2}{2x+5}=\dfrac{76}{17}\)

\(\Rightarrow221x-34=152x+380\)

\(\Rightarrow69x=414\Rightarrow x=6\)

 

19 tháng 10 2019

a) \(\left(-\frac{3}{5}\right)^{14}:\left(-\frac{3}{5}\right)^{13}\)

\(=\left(-\frac{3}{5}\right)^{14-13}\)

\(=\left(-\frac{3}{5}\right)^1\)

\(=-\frac{3}{5}.\)

Chúc bạn học tốt!

19 tháng 10 2019

a) \(\left(\frac{-3}{5}\right)^{14}:\left(\frac{-3}{5}\right)^{13}=\frac{-3}{5}\)

3: 

\(=\dfrac{1}{7}\cdot\dfrac{3}{5}\cdot\dfrac{5}{6}\cdot\dfrac{5}{8}=\dfrac{1}{7}\cdot\dfrac{1}{2}\cdot\dfrac{5}{8}=\dfrac{5}{112}\)

4:

=>2/3:x=-2-1/3=-7/3

=>x=-2/3:7/3=-2/7

5:

AC=CB=12/2=6cm

IB=6/2=3cm

10 tháng 2 2018

a)4x-3=4-3x

<=>4x+3x=4+3

<=>7x=7

<=>x=1

12 tháng 2 2018

\(\text{b)3+x-5=}6x-4\Leftrightarrow x-6x=-4+5-3\Leftrightarrow-5x=-2\Leftrightarrow x=\dfrac{2}{5}\)

vậy S=\(\left\{\dfrac{2}{5}\right\}\)

HQ
Hà Quang Minh
Giáo viên
17 tháng 9 2023

a)

\(\dfrac{1}{2}{x^2}.\dfrac{6}{5}{x^3} = \dfrac{1}{2}.\dfrac{6}{5}.{x^2}.{x^3} = \dfrac{3}{5}{x^5}\);                                                   

b)

\(\begin{array}{l}{y^2}(\dfrac{5}{7}{y^3} - 2{y^2} + 0,25) = {y^2}.\dfrac{5}{7}{y^3} - {y^2}.2{y^2} + {y^2}.0,25)\\ = \dfrac{5}{7}{y^5} - 2{y^4} + 0,25{y^2}\end{array}\);

c)

\(\begin{array}{l}(2{x^2} + x + 4)({x^2} - x - 1) \\= 2{x^2}({x^2} - x - 1) + x({x^2} - x - 1) + 4({x^2} - x - 1)\\ = 2{x^4} - 2{x^3} - 2{x^2} + {x^3} - {x^2} - x + 4{x^2} - 4x - 4 \\= 2{x^4} - {x^3} + {x^2} - 5x - 4\end{array}\);                                                               

d)

\(\begin{array}{l}(3x - 4)(2x + 1) - (x - 2)(6x + 3) \\= 3x(2x + 1) - 4(2x + 1) - x(6x + 3) + 2(6x + 3)\\ = 6{x^2} + 3x - 8x - 4 - 6{x^2} - 3x + 12x + 6\\ = 4x + 2\end{array}\).

18 tháng 1 2019

1)6x-8=3x+1

6x-3x=1+8

3x=9

x=3

Vậy x=3

2: 12-10x=25-30x

=>20x=13

=>x=13/20

3: \(3\left(2x+3\right)-2\left(4x-5\right)=10x+21\)

=>6x+9-8x+10=10x+21

=>10x+21=-2x+19

=>12x=-2

=>x=-1/6

4: \(\Leftrightarrow25x-15-6x+12=11-5x\)

=>19x-3=11-5x

=>24x=14

=>x=7/12

5: \(\Leftrightarrow8-12x-5+10x=4-6x\)

=>4-6x=-2x+3

=>-4x=-1

=>x=1/4

6: \(\Leftrightarrow32x-24-6+9x=13-40x\)

=>41x-30=13-40x

=>81x=43

=>x=43/81

7: \(\Leftrightarrow10x-5+20x=5x-11\)

=>30x-5=5x-11

=>25x=-6

=>x=-6/25

24 tháng 1 2018

a)   \(4x-3=4-3x\)

\(\Leftrightarrow\)\(7x=7\)

\(\Leftrightarrow\)\(x=7\)

Vậy...

b)    \(3+\left(x-5\right)=2\left(3x-2\right)\)

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

\(\Leftrightarrow\)\(5x=2\)

\(\Leftrightarrow\)\(x=\frac{2}{5}\)

Vậy...