a) \(1,25:0,8=\frac{3}{8}:0,2x\)

\(\Rightarrow\frac{3}{8}:0,2x=\frac{25}{16}\)

\(\Rightarrow0,2x=\frac{3}{8}:\frac{25}{16}=\frac{6}{25}\)

\(\Rightarrow x=\frac{6}{25}:\frac{1}{5}=\frac{6}{5}\)

b) \(1,8:1,3=\left(-2,7\right):5x\)

\(\Rightarrow\frac{-27}{10}:5x=\frac{18}{13}\)

\(\Rightarrow5x=\frac{-27}{10}:\frac{18}{13}=\frac{-39}{20}\)

\(\Rightarrow x=\frac{-39}{100}\)

Tính phải k nhỉ?

`1)`

`2x + 3x + 5x`

`= (2 + 3 + 5)x`

`= 10x`

`2)`

`2.x - x + 3.x`

`= (2 - 1 + 3)x`

`= 4x`

`3)`

`9.x - 3 - 3.x`

`= (9 - 3)x - 3`

`= 6x - 3`

`4)`

Thiếu dấu, bạn bổ sung thêm

`5)`

`x - 0,2x - 0,1x`

`= (1 - 0,2 - 0,1)x`

`=0,7x`

`6)`

\(\dfrac{7}{2}x-\dfrac{1}{2}x=\left(\dfrac{7}{2}-\dfrac{1}{2}\right)x=3x\)

a: =>x-2=0 hoặc x+3=0

=>x=2 hoặc x=-3

b:=>x-7=0 hoặc x+2=0

=>x=7 hoặc x=-2

c: =>4x+2=0 hoặc 3x-4=0

=>x=4/3 hoặc x=-1/2

d: =>2x+1=0 hoặc x-3=0

=>x=3 hoặc x=-1/2

a)

`(x-2)(x+3)=0`

`<=> x-2=0` hoặc `x+3=0`

`<=>x=2` hoặc `x=-3`

b)

`(x-7)(2+x)=0`

`<=>x-7=0` hoặc `2+x=0`

`<=>x=7` hoặc `x=-2`

c)

`(4x+2)(3x-4)=0`

`<=>4x+2=0` hoặc `3x-4=0`

`<=>x=-1/2` hoặc `x=4/3`

d)

`(2x+1)(x-3)=0`

`<=>2x+1=0` hoặc `x-3=0`

`<=>x=-1/2` hoặc `x=3`

e)

`(0,1x-3)(x+0,5)=0`

`<=>0,1x-3=0` hoặc `x+0,5=0`

`<=>x=30` hoặc `x=-0,5`

f)

`(0,2x-0,4)(0,1x+0,7)=0`

`<=>0,2x-0,4=0` hoặc `0,1x+0,7=0`

`<=>x=2` hoặc `x=-7`

a, \(-\dfrac{1}{3}x^2y.\dfrac{2}{3}xy^3\)

\(=-\dfrac{2}{9}x^3y^4\)

b, \(-5xy^4.\left(-0,2x^2y^2\right)\)

\(=x^3y^6\)

a)\(-\dfrac{2}{9}x^3y^4\)

b)\(x^3y^6\)

\(a.12-\left|x-3\right|=5x+\)\(8\)

\(\Leftrightarrow\left|x-3\right|=5x+8-12\)

\(\Leftrightarrow\left|x-3\right|=5x-4\)

\(\Leftrightarrow\orbr{\begin{cases}x-3=5x-4\\x-3=-5x+4\end{cases}\Rightarrow\orbr{\begin{cases}x=\frac{1}{4}\\x=\frac{7}{6}\end{cases}}}\)

\(b.3-\frac{0.2x}{5}=\frac{7}{15}+1,4x\)

\(\Leftrightarrow\frac{15-0,2x}{5}=\frac{7+21x}{15}\)

\(\Leftrightarrow15.\left(15-0,2x\right)=5.\left(7+21x\right)\)

\(\Leftrightarrow225-3x=35+105x\)

\(\Leftrightarrow-3x-105x=35-225\)

\(\Leftrightarrow-108x=-190\)

\(\Rightarrow x=\frac{95}{54}\)

nhu con cac

Băng bao nhiêu bạn tớ đang gấp

\(\dfrac{1}{5}x-\dfrac{2}{3}x-\dfrac{2}{3}-\dfrac{1}{3}=0\)

\(\Leftrightarrow\dfrac{-7}{15}x-1=0\)

\(\Leftrightarrow\dfrac{-7x}{15}=1\)

\(\Leftrightarrow x=\dfrac{-15}{7}\)

0,2x - \(\dfrac{2}{3}x\)- \(\dfrac{2}{3}\)=\(\dfrac{1}{3}\)

<=> \(\dfrac{-1,4}{3}\)x=1

<=> x = \(\dfrac{-3}{1,4}\)

25/16=3/8:0,2x

3/8:25/16=0,2x

6/25=0,2x

6/25:0,2=x

6/5=x

\(\dfrac{1}{2}x+0,2x-x-\dfrac{1}{5}=2\dfrac{3}{5}\\ \dfrac{1}{2}x+0,2x-x-\dfrac{1}{5}=\dfrac{13}{5}\\ x\cdot\left(\dfrac{1}{2}+0,2-1\right)=\dfrac{14}{5}\\ x\cdot\left(\dfrac{5}{10}+\dfrac{2}{10}+\dfrac{10}{10}\right)=\dfrac{14}{5}\\ x\cdot\dfrac{17}{10}=\dfrac{14}{5}\\ x=\dfrac{14}{5}:\dfrac{17}{10}\\ x=\dfrac{14}{5}\cdot\dfrac{10}{17}\\ x=\dfrac{28}{17}\)