x/30 + 4/5= 79/30

x/30 = 79/30 - 4/5

x/30= 11/6

11/6= 55/30

=> x= 55

x : 1/3 = 1/2 +1/3

=>x:1/3=5/6

=>x=5/6 x 1/3

=>x=5/18

(x:2/3):2/5=7/10

=>x:2/3=7/10 x 2/5 

=>x:2/3=7/25

=>x=7/25x2/3

=>x=14/75

CHÚC BẠN HỌC TỐT

cái này vừa gửi rồi mà:D

x:1/3=1/2+1/3
x:1/3=5/6
x      =5/6.1/3
x      =5/18
 

(x:2/3):2/5=7/10
x:2/3        =7/10.2/5
x:2/3        =7/25
x:2/3        =7/25.2/3
x:2/3        =14/75
 

\(x+\left(x+1\right)+\left(x+2\right)+...+19+20=20\)

\(\Leftrightarrow x+\left(x+1\right)+\left(x+2\right)+...+19=0\)

\(\Leftrightarrow\frac{x\left(19+x\right)}{2}=0\)

\(\Leftrightarrow x\left(x+19\right)=0\)

\(\Leftrightarrow\orbr{\begin{cases}x=0\\x+19=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=0\\x=-19\end{cases}}\)

Mà \(x\ne0\)nên \(x=-19\)

\(x:33=\dfrac{9}{66}\)
\(x=\dfrac{9}{66}\times33\)
\(x=\dfrac{9}{2}\)
\(\dfrac{4}{5}\times x=\dfrac{10}{11}:\dfrac{3}{4}\)
\(\dfrac{4}{5}\times x=\dfrac{40}{33}\)
\(x=\dfrac{40}{33}:\dfrac{4}{5}\)
\(x=\dfrac{50}{33}\)
#Đạt Đang Bận Thở

x:x+9<xX5<20

1+9<xX5<20

10<xX5<20

2X5<xX5<4X5

x=3

=98 nha ban

X=3 nha bạn

=>10x=9,78

hay x=0,978

x = 4

\(x+\left|-3\right|=-\left|-7\right|\)

\(x+3=-7\)

\(x=-7-3\)

\(x=-10\)

x^3+1=9

x^3=8

x^3=2^3

=>x=2

=>x³=8

hay x=2

`x^3+1=9`

`x^3=8`

`x^3=2^3`

`=>x=2`