\(a,\left(x+3\right)\left(5-x\right)=0\\ \Rightarrow\left\{{}\begin{matrix}x+3=0\\5-x=0\end{matrix}\right.\Rightarrow\left\{{}\begin{matrix}x=-3\\x=5\end{matrix}\right.\)

\(c,x+17⋮x+3\\ x+3+14⋮x+3\\ 14⋮x+3\\ x+3\inƯ\left(14\right)=\left\{\pm14;\pm7\pm2;\pm1\right\}\)

Từ đó bạn tìm những giá trị của x nha!

a: \(\Leftrightarrow\dfrac{x}{-4}=\dfrac{21}{y}=\dfrac{z}{-80}=\dfrac{3}{4}\)

=>x=-3; y=28; z=-60

b: 5/12=x/-72

=>x=-72*5/12=-6*5=-30

c: =>x+3=-5

=>x=-8

a)

\(x+\left(x+2\right)+\left(x+4\right)+...+\left(x+98\right)=0\)

\(x+x+2+x+4+...+x+98=0\)

\(50x+\left(98+2\right).\left[\left(98-2\right):2+1\right]:2=0\)

\(50x+100.49:2=0\)

\(50x+49.50=0\)

\(50x=0-49.50\)

\(50x=-2450\)

\(x=-2450:50\)

\(x=-49\)

b)

\(\left(x-5\right)+\left(x-4\right)+\left(x-3\right)+...+\left(x+11\right)+\left(x+12\right)=99\)

\(x+x+x+...+x-5-4-3-...+11+12=99\)

\(18x+6+7\text{+ 8 + 9 + 10 + 11 + 12 = 99}\)

\(18x+63=99\)

\(18x=99-63\)

\(18x=36\)

\(x=36:18\)

\(x=2\)

giúp mình với, mình đang vội!

a) x + (x + 2) + (x + 4) + ... + (x + 98) = 0

x + x + 2 + x + 4 + ... + x + 98 = 0

50x + (98 + 2).[(98 - 2) : 2 + 1]:2 = 0

50x + 100 .49 : 2 = 0

50x + 49.50 = 0

50x = 0 - 49.50

50x = -2450

x = -2450 : 50

x = -49

b) (x - 5) + (x - 4) + (x - 3) + ... + (x + 11) + (x + 12) = 99

x + x + x + ... + x - 5 - 4 - 3 - ... + 11 + 12 = 99

18x + 6 + 7 + 8 + 9 + 10 + 11 + 12 = 99

18x + 63 = 99

18x = 99 - 63

18x = 36

x = 36 : 18

x = 2

a, |x - 5| = x - 5 ( đk : x >= 5 ) 
<=> x - 5 = ( x - 5 )^2 
<=> x - 5 = x^2 - 10x + 25 
<=> x^2 - 10x + 25 - x + 5 = 0 
<=> x^2 - 11x + 30 = 0 
<=> x^2 - 5x - 6x + 30 = 0 
<=> ( x^2 - 5x) - ( 6x - 30) = 0 
<=> x ( x- 5) - 6( x- 5 ) = 0 
<=> ( x- 5).(x - 6) =0 
<=> Th1 : x- 5 = 0 => x = 5 
Th2 : x - 6 = 0 => x = 6

khó kinh

a)Ta có :

\(\left|x-5\right|\ge0\)

\(\Rightarrow5-x\ge0\)

Mà 5 > 0

\(\Rightarrow x\ge0\)

Nên |x - 5| = 5 - x

=> x - 5 = 5 - x

=> x + x = 5 + 5

=> 2x = 10

=> x = 5

b) Ta có :

\(\left|x+3\right|\ge0\)

\(\left|x+2\right|\ge0\)

\(\Rightarrow\left|x+3\right|+\left|x+2\right|\ge0\)

\(\Rightarrow x\ge0\)

Nên |x + 3| + |x + 2| = x

=> x + 3 + x + 2 = x

=> 2x + 5 = x

=> 2x - x = -5

=> x = -5

a, Đặt x-5 = y

Ta có |y|=-y

Do đó y =<0

Hay x-5=<0

tương đương x bé hơn hoặc bằng 5

-29-9(2x-1)\(^2\)= -110

(=) 9(2x-1)² = (-29) +110

(=) 9(2x-1)² = 81

(=) (2x-1)² =81: 9

(=) (2x-1)² =9

(=) (2x-1)² = 3² =(-3)²

\(\orbr{\begin{cases}2x-1=3\\2x-1=-3\end{cases}}\)

\(\orbr{\begin{cases}2x=4\\2x=-2\end{cases}}\)

\(\orbr{\begin{cases}x=2\\x=-1\end{cases}}\)

vậy : ........

a,\(-29-9\left(2x-1\right)^2=-110\)

\(=>-29+110=9.\left(2x-1\right)^2\)

\(=>81=9.\left(2x-1\right)^2\)

\(=>\left(2x-1\right)^2=9\)

\(=>\orbr{\begin{cases}2x-1=3\\2x-1=-3\end{cases}=>\orbr{\begin{cases}x=\frac{4}{2}=2\\x=\frac{-2}{2}=-1\end{cases}}}\)

b,\(-2.\left(-x-5\right)+28=20-3.4\)

\(=>2x+10+28=20-12=8\)

\(=>2x=8-28-10=-30\)

\(=>x=\frac{-30}{2}=-15\)

Bài 2 : a, x = -36/9 = -4

b, đề sai 

c, <=> -2 =< x =< -3 => x = -1 

Bài 1: 

a: 2/8=9/36; 2/9=8/36; 8/2=36/9; 9/2=36/8

b: -2/4=9/-18; -2/9=4/-18; 4/-2=-18/9; 9/-2=-18/4

Bài 2: 

a: =>x/3=-4/3

hay x=-4

Câu b đề sai rồi bạn

a: \(n\in\left\{1;-1\right\}\)