\(\frac{2x+3}{6}=\frac{7x-3}{15}\)

\(15\left(2x+3\right)=6\left(7x-3\right)\)

\(30x+45=42x-18\)

\(30x-42x=-18-45\)

\(-12x=-63\)

\(x=\frac{21}{4}\)

     \(\frac{2x+3}{6}=\frac{7x-3}{15}\)

\(\Rightarrow\frac{5.\left(2x+3\right)}{30}=\frac{2.\left(7x-3\right)}{30}\)

\(\Rightarrow5.\left(2x+3\right)=2.\left(7x-3\right)\)

\(\Rightarrow10x+15=14x-6\)

\(\Rightarrow10x-14x=-6-15\)

\(\Rightarrow-4x=-21\)

\(\Rightarrow x=-21:\left(-4\right)\)

\(\Rightarrow x=\frac{21}{4}\)

\(\frac{\left(2x+3\right)}{6}=\frac{\left(7x-3\right)}{15}\)

\(\Leftrightarrow\left(2x+3\right).15=\left(7x-3\right).6\)

\(\Leftrightarrow30x+45=42x-18\)

\(\Leftrightarrow42x-30x=45+18\)

\(\Leftrightarrow12x=63\)

\(\Leftrightarrow x=\frac{21}{4}=5,25\)

1) (3x + 9)(3x - 6) = 0

=> \(\orbr{\begin{cases}3x+9=0\\3x-6=0\end{cases}}\)

=> \(\orbr{\begin{cases}3x=-9\\3x=6\end{cases}}\)

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

Vậy ...

b) (2x + 15) - 25 = 47 - (10 - x)

=> 2x  - 10 = 37 + x

=> 2x - x = 37 + 10

=> x = 47

3, tương tự

4) |4 - 3x| = 8

=> \(\orbr{\begin{cases}4-3x=8\\4-3x=-8\end{cases}}\)

=> \(\orbr{\begin{cases}3x=-4\\3x=12\end{cases}}\)

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

Vì x là số nguyên nên ...

còn lại tương tự

a) 2x + 23x = 625

   x (2 + 23) = 625

   x. 25        = 625

             x    = 625 : 25

             x    = 25

b) (2^2+4^2) x +2^4 x 5 * x = 100 (dấu* là dấu nhân vì mik không muốn trùng nhau nên viết vậy)

    ( 4 + 16 ) x + 2^4 x 5 * x = 100

         20 * x +   16 x 5 * x =100

            x ( 20 + 16 x 5 )  = 100

           x ( 20 + 80 ) = 100

           x * 100 =100

                   x=100 : 100

                   x= 1

c) ( 3x +1)^2 = 6^2+8^2

    (3x +1)^2  = 36 +64

    (3x +1)^2   =100

     (3x +1)^2  = 10^2

           3x + 1 =10

                  3x=10 - 1=9

                    x = 9 :3

                    x = 3

( d và e làm tương tự )

k mik nha!

Dể mà,k mik mik giải cho

Giai giup minh di ban

⇔(2 x ) ²+2.2 x .1+1 ²=0 ... c ,(3 x −4) ²−14(3 x −4)(6+3 x )+49(3 x +6)=16 ... ⇔9 x ²−24 x +16−126 x ²−252 x +168 x +336+147 x +294=16.

https://olm.vn/hoi-dap/detail/192758180810.html

\(-2x\left(6x-2\right)+3x\left(4x-7\right)=8\)

<=> \(-12x^2+4x+12x^2-21x=8\)

<=> \(-17x=8\)

<=> \(x=-\frac{8}{17}\)

\(\left(7x-2\right)\left(2x+3\right)-\left(3x-5\right)\left(4x+6\right)=2x^2-5\)

<=> \(14x^2+17x-6-12x^2+2x+30=2x^2-5\)

<=> \(14x^2+17x-6-12x^2+2x+30-2x^2+5=0\)

<=> \(19x+29=0\)

<=> \(19x=-29\)

<=> \(x=-\frac{29}{19}\)

Ý cuối mình k biết -22x2 là -22.2 hay -22x² nữa :)

Bài 1: 

5²⁰ : [ 5¹⁵ . 6 + 5¹⁵ . 19 ]

= 5²⁰ : [ 5¹⁵ . ( 6 + 19 ) ]

= 5²⁰ : [ 5¹⁵ . 25 ] 

= 5²⁰ : [ 5¹⁵ . 5² ]

= 5²⁰ : 5¹⁷

= 5³

Bài 2 

a) 5x + x = 39 - 3¹¹ : 3⁹

=> 6x = 39 - 3²

=> 6x = 39 - 9

=> 6x = 30

=> x = 5

b) 7x - x = 5²¹ : 5¹⁹ + 3 . 2² - 7⁰

=> 6x = 5² + 3 . 4 - 1

=> 6x = 25 + 12 - 1

=> 6x = 36

=> x = 6

c) 7x - 2x = 6¹⁷ : 6¹⁵ + 44 : 11

=> ( 7 - 2 )x = 6² + 4

=> 5x = 36 + 4

=> 5x = 40

=> x = 8

1. \(5^{20}:\left(5^{15}.6+5^{15}.19\right)=5^{20}:\left\{5^{15}\left(6+19\right)\right\}\)

   \(=5^{20}:\left\{5^{15}.25\right\}=5^{20}:\left\{5^{15}.5^2\right\}\)

   \(=5^{20}:5^{17}=5^3=125\)

5x+x = 39-3¹¹:3⁹

=> x(5+1) = 39-3²

=> 6x=30

=> x=5

7x-x = 5²¹:5¹⁹+3.2²-7⁰

=> x(7-1)= 5²+3.4-1

=> 6x = 36

=> x=6

7x-2x = 6¹⁷:6¹⁵+44:11

=> x(7-2) = 6²+4

=> 5x = 40

=> x= 8

 \(2x+6=0\\ \Leftrightarrow2x=-6\\ \Leftrightarrow x=-3\)

\(4x+20=0\\ \Leftrightarrow4x=-20\\ \Leftrightarrow x=-5\)

\(2x-3=0\\ \Leftrightarrow2x=3\\ \Leftrightarrow x=\dfrac{3}{2}\)

\(15-7x=9-3x\\ \Leftrightarrow15-7x-9+3x=0\\ \Leftrightarrow6-4x=0\\ \Leftrightarrow-4x=-6\\ \Leftrightarrow x=\dfrac{3}{2}\)

\(3x-1=x+3\\ \Leftrightarrow3x-1-x-3=0\\ \Leftrightarrow2x-4=0\\ \Leftrightarrow2x=4\\ \Leftrightarrow x=2\)

(Lưu ý khi đăng câu hỏi: bạn phải phân chia các bài ra trước khi đăng ví dụ như bài trên bạn phải phân chia theo thứ tự câu a,b,c,...)

1/ ĐKXĐ : \(x\ne1\)

\(\dfrac{7x-3}{x-1}=\dfrac{2}{3}\)

\(\Leftrightarrow21x-9=2x-2\)

\(\Leftrightarrow19x=7\Leftrightarrow x=\dfrac{7}{19}\left(tm\right)\)

Vậy...

b/ \(\dfrac{2\left(3-7x\right)}{1+x}=\dfrac{1}{2}\) ĐKXĐ : \(x\ne-1\)

\(\Leftrightarrow12-28x=1+x\)

\(\Leftrightarrow11=29x\Leftrightarrow x=\dfrac{11}{29}\) \(\left(tm\right)\)

Vậy....

c/ ĐKXĐ : \(x\ne0\)

\(\dfrac{x^2-6}{x}=x+\dfrac{3}{2}\)

\(\Leftrightarrow\dfrac{x^2-6}{x}=\dfrac{2x+3}{2}\)

\(\Leftrightarrow2x^2-12=2x^2+3x\)

\(\Leftrightarrow3x=-12\Leftrightarrow x=-4\) \(\left(tm\right)\)

Vậy...

4/ ĐKXĐ : \(x\ne-\dfrac{2}{3}\)

\(\dfrac{5}{3x+2}=2x-1\)

\(\Leftrightarrow\left(2x-1\right)\left(3x+2\right)=5\)

\(\Leftrightarrow6x^2+4x-3x-2=5\)

\(\Leftrightarrow6x^2+x-7=0\Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{7}{6}\\x=1\end{matrix}\right.\)

Vậy....

5,6 Tương tự nhé !

1)ĐKXĐ: \(x\ne1\)

Ta có: \(\dfrac{7x-3}{x-1}=\dfrac{2}{3}\)

\(\Leftrightarrow3\left(7x-3\right)=2\left(x-1\right)\)

\(\Leftrightarrow21x-9=2x-2\)

\(\Leftrightarrow21x-9-2x+2=0\)

\(\Leftrightarrow19x-7=0\)

\(\Leftrightarrow19x=7\)

\(\Leftrightarrow x=\dfrac{7}{19}\)(nhận)

Vậy: \(S=\left\{\dfrac{7}{19}\right\}\)

2) ĐKXĐ: \(x\ne-1\)

Ta có: \(\dfrac{2\left(3-7x\right)}{1+x}=\dfrac{1}{2}\)

\(\Leftrightarrow4\left(3-7x\right)=x+1\)

\(\Leftrightarrow12-28x-x-1=0\)

\(\Leftrightarrow-29x+11=0\)

\(\Leftrightarrow-29x=-11\)

\(\Leftrightarrow x=\dfrac{11}{29}\)

Vậy: \(S=\left\{\dfrac{11}{29}\right\}\)

3) ĐKXĐ: \(x\ne0\)

Ta có: \(\dfrac{x^2-6}{x}=x+\dfrac{3}{2}\)

\(\Leftrightarrow\dfrac{x^2-6}{x}=\dfrac{2x+3}{2}\)

\(\Leftrightarrow2\left(x^2-6\right)=x\left(2x+3\right)\)

\(\Leftrightarrow2x^2-12=2x^2+6x\)

\(\Leftrightarrow2x^2-12-2x^2-6x=0\)

\(\Leftrightarrow-6x-12=0\)

\(\Leftrightarrow-6x=12\)

\(\Leftrightarrow x=-2\)

Vậy: S={-2}