Ta có : \(\frac{x-99}{5}+\frac{x-99}{15}+\frac{x-99}{25}+\frac{x-99}{35}=0\)

\(\Rightarrow\left(x-99\right)\left(\frac{1}{5}+\frac{1}{15}+\frac{1}{25}+\frac{1}{35}\right)=0\)

Vì \(\frac{1}{5}+\frac{1}{15}+\frac{1}{25}+\frac{1}{35}\ne0\)

Nên : x - 99 = 0

Suy ra : x = 99

Vậy x = 99

giải hộ mik với min hf rất cần

Ta có : 

\(\frac{x-99-1}{99}-\frac{x-99-1}{98}-\frac{x-99-1}{97}-\frac{x-99-1}{96}-\frac{x-99-1}{95}-\frac{x-99-1}{94}=0\)

\(\Leftrightarrow\)\(\frac{x-100}{99}-\frac{x-100}{98}-\frac{x-100}{97}-\frac{x-100}{96}-\frac{x-100}{95}-\frac{x-100}{94}=0\)

\(\Leftrightarrow\)\(\left(x-100\right)\left(\frac{1}{99}-\frac{1}{98}-\frac{1}{97}-\frac{1}{96}-\frac{1}{95}-\frac{1}{94}\right)=0\)

Vì \(\frac{1}{99}-\frac{1}{98}-\frac{1}{97}-\frac{1}{96}-\frac{1}{95}-\frac{1}{94}\ne0\)

Nên \(x-100=0\)

\(\Rightarrow\)\(x=100\)

Vậy \(x=100\)

Bài làm mang tính chất tham khảo vì em mới lớp 7 ~

cau1: 99-2=97

Cau 2: x=99x3=297 vay x=297

cau 3: x:21=14

x=21x14

x=294

sai đe roi ban oi

99 - 2 = x

 Vậy 99 -2 = 97

Vậy x = 97

x - 99 x 3 = 0

x - 99 =0 bởi vì 0 : 3 = 0 

X = 0 + 99 = 99

x = 14 x 21

x = 294

tích mik mik tích lại

\(x^{99}-x^{97}=0\Leftrightarrow x^{97}\cdot\left(x^2-1\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x^{97}=0\\x^2-1=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\\x=\pm1\end{matrix}\right.\)

(99+x).(x^2-16)=0
<=> (x-4).(x+4).(99+x)=0
<=> x-4=0 => x=4
       x+4=0 => x=(-4)
       99+x=0 => x=(-99)
vậy x thuộc (4;-4;-99)

( 99 + x ).( x² -16) = 0

TH1: 99 + x = 0

                 x = 0 - 99

                 x = -99

TH2:   x² - 16 = 0 

                   x² = 0 + 16

                   x² = 16 

                   x² = 4²

            =>   x = 4

Vậy....

\(\left(x+1\right)+\left(x+3\right)+\left(x+5\right)+...+\left(x+99\right)=0\\ \left(x+x+...+x\right)+\left(1+3+5+...+99\right)=0\\ 50x+2500=0\\ x=-50\)

Vậy x = -50

Ta có: \(\left(x+1\right)+\left(x+3\right)+...+\left(x+99\right)=0\)

\(\Leftrightarrow50x=-2500\)

hay x=-50

`(x+1)+(x+3)+(x+5)+.....+(x+99)=0`

`=>(x+x+.....+x)+(1+3+5+......+99)=0`

`=>50x+(100.50)/2=0` (do từ 1 đến 99 có 50 số nên vì vậy cũng có 50x)

`=>50x+50.50=0`

`=>50(x+50)=0`

`=>x+50=0`

`=>x=-50`

Vậy `x=-50`

(x+1)+(x+3)+(x+5)+...+(x+99)=0

<=> 50x + (1+99) x 25=0

<=>50x+ 2500=0

<=>50x= -2500

<=>x= -50 

=>S={-50}

\(\left(x+1\right)+\left(x+3\right)+\left(x+5\right)+....+\left(x+99\right)=0\)

\(\Leftrightarrow\left(x+x+x+....+x\right)+\left(1+3+5+...+99\right)=0\)

\(\Leftrightarrow50x+2500=0\)

\(\Leftrightarrow x=-50\)

cau 1 :

Tu dau bai ta co:

 X x 50 + ( 100 + 2 ) x 50 : 2 = 2700

 X x 50 + 2550 = 2700

X x 50 = 2700 - 2550

X x 50 = 150

X = 150 : 50

X = 3

Bai 2 

1 ) ( 99 + 0 ) x 100 : 2 = 4950

2 ) ( 99 + 1 ) x 99 : 2 = 4950

3 )    day tren co so cac so hang la :

              ( 99 - 1 ) : 2 + 1 = 50 ( so )

Vay tong la : ( 99 + 1 ) x 50 : 2 = 2500

lik e cho minh nha moi nguoi