\(x-4=26\\ \Leftrightarrow x=30\)

\(\left(40+x\right).2=180\\ \Leftrightarrow40+x=90\\ \Leftrightarrow x=50\)

\(\left(14+5x\right):2=3^5:3^2\\ \Leftrightarrow\left(14+5x\right):2=27\\ \Leftrightarrow14+5x=54\\ \Leftrightarrow5x=40\\ \Leftrightarrow x=8\)

ghê

vừa hãy thấy gửi rồi mà
Spam à:D?

cái này tớ làm rồi mà

spam nha, lm cho r mà

tui đang xóa

Ta có : \(\frac{x}{-5}=\frac{-180}{x}\)

\(\Rightarrow x.x=\left(-180\right).\left(-5\right)\)

\(\Rightarrow x^2=900\)

\(\Rightarrow\left[\begin{array}{nghiempt}x=\sqrt{900}\\x=-\sqrt{900}\end{array}\right.\Rightarrow\left[\begin{array}{nghiempt}x=30\\x=-30\end{array}\right.\)

Vậy \(x=30;-30\)

\(\frac{x}{-5}=\frac{-180}{x}\)

\(\Rightarrow x^2=900\)

\(\Rightarrow x=\pm30\) (có nghĩa là x=30 hc x=-30)

Câu a sai để rồi phải đủ 15 mới đúng chu

b) xX= 645-444=201

c) 1482:X = 80-23 = 57

suy ra  X= 1482: 57= 26

    \(\)

a, 890:x=35 dư 5

  x= 890x5

  x= 31150+5

  x= 31155

b, 645-x=444

-x= 444-645

-x=-201

=> x= 201

c, 1482:x+23=80

    1482:x= 80-23

     1482:x= 57

             x= 57x1482

             x= 73074

Tk cho mk nhé -))

99,99<44+0,xx+xx+0,44<122,21

_{99,99<(44+0,44)+(0, xx+xx)<122,21}

_{99,99<44,44+xx,xx<122,21}

_{99,99-44,44<xx,xx<122,21-44,44}

55,55<xx,xx<77,77 vì xx,xx là số có các chữ số giống nhau nên xx,xx=66,66=> x=6

Đặt:

\(\dfrac{x}{4}=\dfrac{y}{5}=k\)

\(\Rightarrow\left\{{}\begin{matrix}x=4k\\y=5k\end{matrix}\right.\)

\(\Rightarrow x+y=4k+5k\)

\(\Rightarrow9k=180\Rightarrow k=20\)

\(\Rightarrow\left\{{}\begin{matrix}x=20.4=80\\y=20.5=100\end{matrix}\right.\)

Ta có :

\(\dfrac{x}{4}=\dfrac{y}{5}\) và \(x+y=180\)

Áp dụng t/c dãy tỉ số bằng nhau ta có :

\(\dfrac{x}{4}=\dfrac{y}{5}=\dfrac{x+y}{4+5}=\dfrac{180}{9}=20\)

\(\left[{}\begin{matrix}\dfrac{x}{4}=20\Rightarrow x=80\\\dfrac{y}{5}=20\Rightarrow y=100\end{matrix}\right.\)

a,  \(\overline{xx}+x+5=125\)

      \(x\times11+x=120\)

      \(x\left(1+11\right)=120\)

      \(x=120\div12\)

      \(x=10\)

  Vậy x = 10

\(\overline{xxx}+\overline{xx}+x+x=992\)

\(x\times111+x\times11+x\times2=992\)

\(x\left(111+11+2\right)=992\)

 \(x=992\div124\)      

\(x=8\)

 Vậy x = 8

\(4725+\overline{xxx}+\overline{xx}+x=54909\)

\(x\times111+x\times11+x=50184\)

\(x\left(111+11+1\right)=50184\)

\(x\times123=50184\)

\(x=408\)

Vậy x = 408

b,  \(\overline{xxx}-\overline{xx}-x-25=4430\)

\(x\times111-x\times11-x=4455\)

\(x\left(111-11-1\right)=4455\)

\(x=4455\div99\)

\(x=45\)

Vậy x = 45

\(\overline{xxx}+\overline{xx}+x+x+x+1=1001\)

\(x\times111+x\times11+x\times3=1000\)

\(x\left(111+11+3\right)=1000\)

\(x=1000\div125\)

\(x=8\)

Vậy x = 8

\(35655-\overline{xxx}-\overline{xx}-x=5274\)

\(x\times111+x\times11+x=30381\)

\(x\left(111+11+1\right)=30381\)

\(x=30381\div123\)\

\(x=247\)

 Vậy \(x=247\)

xxxx-xx-x-25=4430

xxxx-xx-x    =4430-25(tim so hang)

Xx111-Xx11-x=4405

Xx(111+11+1)=4405

Xx1099=4405

x          =4405:1099(tim thua so)

x            =4(dư 9)