`b, (x + 1)^3 = -125`

` (x + 1)^3 = (-5)^3`

` x + 1 = -5`

` x = -5 - 1`

` x = -6`

Vậy `x = -6`

\(c,3^{4-x}=27\)

\(3^{4-x}=3^3\)

` 4 - x = 3`

` x = 4 - 3`

` x = 1`

Vậy `x = 1`

`a,` mik làm rùi nha

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

\(\left(x-1,2\right)^2=2^2\)

\(x-1,2=2\)

\(x=2+1,2\)

\(x=3,2\)

Vậy `x = 3,2`

\(a,32,8:x=7,2+2,8\)

\(32,8:x=10\)

\(x=32,8:10\)

\(x=3,28\)

`b, x : 22 = 28,7 - 13,5`

` x : 22 = 15,2`

\(x=15,2\times22\)

`x = 334,4`

`c, x` \(\times12,5=\left(32,6-10,4\right):5\)

\(x\times12,5=22,2:5\)

\(x\times12,5=4,44\)

` x = 4,44 : 12,5`

` x = 0,3552`\(=\dfrac{222}{625}\)

Ok e!

Họ cho coin đc nhưng k tick đc nhé

\(\left(x+\dfrac{1}{7}\right):\dfrac{1}{3}=\dfrac{3}{4}\)

\(x+\dfrac{1}{7}=\dfrac{3}{4}.\dfrac{1}{3}\)

\(x+\dfrac{1}{7}=\dfrac{1}{4}\)

\(x=\dfrac{1}{4}-\dfrac{1}{7}\)

\(x=\dfrac{3}{28}\)

Vậy \(x=\dfrac{3}{28}\)

\(\left(\dfrac{21}{8}+\dfrac{1}{2}\right):\dfrac{5}{16}\)

\(=\dfrac{25}{8}:\dfrac{5}{16}\)

\(=\dfrac{25}{8}.\dfrac{16}{5}\)

\(=\dfrac{5}{1}.\dfrac{2}{1}\)

\(=5.2=10\)

Câu `a,` vế phải đâu.

\(b,\left(x+40\right).15=75.12\)

\(\left(x+40\right).15=900\)

\(x+40=900:15\)

`x + 40 = 60`

`x = 60 - 40`

`x = 20`

Vậy `x = 20`

`c, 460 + 85 . 4 = (x + 200) : 4`

` 460 + 340 = (x + 200) : 4`

` 800 = (x + 200) : 4`

`800 . 4 = x + 200`

` 3200 = x + 200`

` x = 3200 - 200`

` x = 3000`

Vậy `x = 3000` 

`d, x - 4300 - (5250 : 1050 . 250) = 4250`

` x - 4300 - (5 . 250) = 4250`

` x - 4300 - 1250 = 4250`

` x - 4300 = 4250 + 1250`

` x - 4300 = 5500`

`x = 5500 + 4300`

`x = 9800`

Vậy `x = 9800`

`e, x - 6 .(48 - 24 . 2 : 6 - 3) = 100`

` x - 6 . (48 - 48 : 6 - 3) = 100`

` x - 6 . (48 - 8 - 3) = 100`

` x - 6 . (40 - 3) = 100`

` x - 6 . 37 = 100`

` x - 222 = 100`

` x = 100 + 222`

` x = 322`

Vậy `x = 322`

 `f, 20 - [7 . (x - 3) + 4] = 2`

` 7 . (x - 3) + 4 = 20 - 2`

` 7 . (x - 3) + 4 = 18`

` 7 . (x - 3) = 18 - 4`

` 7 . (x - 3) = 14`

` x - 3 = 14 : 7`

` x - 3 = 2`

` x = 2 + 3`

` x = 5`

Vậy `x = 5`

Con muỗi -))

Kinchana-))))