e, `-2 / 3` . x + `1 / 5` = `3 / 10`

`-2 / 3` . x = `3 / 10` – `1 / 5`

`-2 / 3` . x = `2 / 5`

x = `2 / 5` : `-2 / 3`

x = `-3 / 5`

f, `1 / 3` + `1 / 3` . (2x – 1) = -5

`2 / 3` . (2x – 1) = -5

(2x – 1) = (-5) : `2 / 3`

(2x – 1) = `-15 / 2`

2x = `-15 / 2` + 1

2x = `-13 / 2`

x = `-13 / 2` : 2

x = `-13 / 4`

g, |2x - `1 / 3`| = `1 / 6`

* Bài này mình không biết làm nhé bạn, thông cảm giúp mình nha!

Bài 5: Tìm x, biết:

a, `5 / 6` + `1 / 4` : x = `-2 / 3`

`1 / 4` : x = `-2 / 3` - `5 / 6`

`1 / 4` : x = `-3 / 2`

x = `1 / 4` . `2 / 3`

x = `1 / 6`

b, x – 43 = (57 – x) – 50

x – 43 = 57 – 50 – x

x – 43 = 7 – x

x + x = 7 + 43

2x = 50

x = 50 : 2

x = 25

c, 25% . x + x = 2`1 / 2`

x . (25% + 1) = `5 / 2`

x . `5 / 4` = `5 / 2`

x = `5 / 2` . `4 / 5`

x = 2

d, |2x – 3| + 12 = (-4)²

|2x – 3| + 12 = 16

|2x – 3| = 16 – 12

|2x – 3| = 4

⇒ TH1:

2x – 3 = 4

2x = 4 + 3

2x = 7

x = 7 : 2

x = `7 / 2`

⇒ TH2:

2x – 3 = -4

2x = (-4) + 3

2x = -1

x = (-1) : 2

x = `-1 / 2`

a) $\dfrac{5}{6}+\dfrac{1}{4}:x=\dfrac{-2}{3}$

$\dfrac{1}{4}:x=\dfrac{-2}{3}-\dfrac{5}{6}$

$\dfrac{1}{4}:x=-\dfrac{3}{2}$

$x=\dfrac{1}{4}.\dfrac{2}{3}=\dfrac{1}{6}$

b) $x-43=(57-x)-50$

$x-43=57-50-x$

$x-43=7-x$

$(x-43)-(7-x)=0$

$x-43-7+x=0$

$2x-50=0$

$2x=50$

$x=25$

c) `25%.x+x=2\frac{1}{2}`

`x(25%+1)=\frac{5}{2}`

$x.\dfrac{5}{4}=\dfrac{5}{2}$

$x=\dfrac{5}{2}.\dfrac{4}{5}=2$

d) $|2x-3|+12=(-4)^2=16$

$|2x-3|=16-12=4$

$⇒TH1:2x-3=4$

$2x=7⇒x=\dfrac{7}{2}$

$⇒TH2:2x-3=-4$

$2x=-1⇒x=-\dfrac{1}{2}$