12 + x / 43 - x có tổng là 12 + 43 = 55

Tổng số phần bằng nhau :

 2 + 3 = 5 ( phần )

 Giá trị 1 phần :

 55 : 5 = 11

x là :

  ( 11 x 2 ) - 12 = 10 

\(\frac{12+x}{43-x}=\frac{2}{3}\)

\(\Leftrightarrow2\left(43-x\right)=3\left(12+x\right)\)

\(\Leftrightarrow86-2x=36+3x\)

\(\Leftrightarrow86-36=3x+2x\)

\(\Leftrightarrow50=5x\Leftrightarrow x=10\)

12 + x / 43 - x có tổng là 12 + 43 = 55

Tổng số phần bằng nhau :

 2 + 3 = 5 ( phần )

 Giá trị 1 phần :

 55 : 5 = 11

x là :

  ( 11 x 2 ) - 12 = 10 

b ) x/5 < 3/7 <=> 7x/35  < 15/35

=> 7x = 14

       x = 2

c ) 1 < 11/x < 2

     11/5 > 2 

=> 5 < x < 11

x { 6 ; 7 ; 8 ; 9 ; 10 }

\(\frac{12+x}{43-x}=\frac{2}{3}\)  
\(\Rightarrow\frac{\left(12+x\right)\times3}{\left(43-x\right)\times3}=\frac{2\times\left(43-x\right)}{\left(43-x\right)\times3}\)  

\(\Rightarrow\frac{36+3x}{129-3x}=\frac{86-2x}{129-3x}\)  

\(\Rightarrow\frac{36+3x}{129-3x}-\frac{86-2x}{129-3x}=0\)  

\(\Rightarrow\frac{36+3x-86+2x}{129-3x}\)  

\(\Rightarrow\frac{-50+5x}{129-3x}\)  

k cho minh

2/3 = 22/33

Vậy x = 22 - 12 = 10

Chúc bạn hok tốt nha!

= 0 hết nhé

\(\frac{12+50}{43+129}=\frac{2}{3}\)

\(\Rightarrow3\left(12+x\right)=2\left(43+x\right)\)

\(\Leftrightarrow36+3x=86+2x\)

\(\Leftrightarrow x=86-36=50\)

bạn ơi 2 x phải bằng nhau nhé 

\(\frac{12+x}{43-x}=\frac{2}{3}\)

2 ( 43 - x ) = 3 ( 12 + x ) 

86 - 2x = 36 + 3x

86 - 36 = 3x + 2x

5x = 50

x = 10

Vậy,......

(12 + x) . 3 = (43 - x) . 2

36 + 3x = 86 - 2x

86 - 36 = 3x + 2x

50 = 5x

x = 50 : 5

x = 10

\(\frac{12+x}{43-x}=\frac{2}{3}\)

=> (12 + x)3 = 2(43 - x)

=> 36 + 3x = 86 - 2x

=> 3x + 2x = 86 - 36

=> 5x = 50

=> x = 10

Tìm x, biết:

3(x+2)(x+5) +5(x+5)(x+10) +7(x+10)(x+17) =x(x+2)(x+17) (x∉−2;−5;−10;−17)

2(x−1)(x−3) +5(x−3)(x−8) +12(x−8)(x−20) −1x−20 =−34 (x∉1;3;8;20)

x+110 +2+111 x+112 =x+113 +x+114 

x−1030 +x−1443 +x−595 +x−1488 =0

Trả lời luôn à bạn

a)\(\frac{x}{17}=\frac{60}{204}=\frac{5}{17}\Rightarrow x=5\)

b)\(\frac{6+x}{33}=\frac{7}{11}\Rightarrow11\left(6+x\right)=7.33\Rightarrow11.6+11x=231\Rightarrow66+11x=231\)

\(\Rightarrow11x=231-66\Rightarrow11x=165\Rightarrow x=\frac{165}{11}=15\)

c)\(\frac{12+x}{43-x}=\frac{2}{3}\Rightarrow2\left(43-x\right)=3\left(12+x\right)\Rightarrow2.43-2x=3.12+3x\)

\(86-2x=36+3x\Rightarrow86-36=3x+2x\Rightarrow50=5x\Rightarrow x=\frac{50}{5}=10\)

\(\frac{12+x}{43-x}=\frac{2}{3}\)\(\Rightarrow3\left(12+x\right)=2\left(43-x\right)\)

\(\Rightarrow36+3x=86-2x\)

\(\Rightarrow36+3x-86+2x=0\)

\(\Rightarrow5x=50\)

\(\Rightarrow x=10\)

\(\frac{12+x}{43-x}=\frac{2}{3}\)

\(\frac{\left(12+x\right)\times3}{\left(43-x\right)\times3}=\frac{2\times\left(43-x\right)}{3\times\left(43-x\right)}\)

\(\left(12+x\right)\times3=2\times\left(43-x\right)\)

\(36+x\times3=86-2\times x\)

\(x\times3+2\times x=86-36\)

\(x\times5=50\)

      \(x=50\div5\)

      \(x=10\)

A/ \(\frac{x}{17}=\frac{60}{204}\)

\(204x=60.17\)

\(204x=1020\)

\(x=\frac{1020}{204}\)

\(x=\frac{17}{4}=4,25\)

vậy x= 4,25

B/ \(\left(6+x\right).11=33.7\)

\(66+11x=231\)

\(11x=231-66=165\)

\(x=\frac{165}{11}\)

\(x=15\)

vậy x = 15

C/ \(\left(12+x\right).3=\left(43-x\right).2\)

\(36+3x=86-2x\)

\(3x+2x=86-36\)

\(5x=50\)

\(x=\frac{50}{5}=10\)

vậy x=10

mk nhầm 

phần a là \(\frac{1020}{204}\)= 5 nha

mk nhầm, xin lỗi