\(3\frac{1}{3}x+16\frac{3}{4}=-13,25\)

\(\frac{10}{3}x+\frac{67}{4}=\frac{-53}{4}\)

\(\frac{10}{3}x=-30\)

\(x=-9\)

\(3\frac{1}{3}x+16\frac{3}{4}=-13,25\)

\(\frac{10}{3}x+\frac{67}{4}=\frac{-53}{4}\)

\(\frac{10}{3}x=-30\)

\(x=-9\)

\(-52+\frac{2}{3}x=-46\)

\(\frac{2}{3}x=-46+52\)

\(\frac{2}{3}x=6\)

\(x=6:\frac{2}{3}\)

\(x=9\)

x=9 nha bn

đúng nha

Happy new year!!

\(\frac{x+3}{-4}=-\frac{9}{x+3}\)

\(\Leftrightarrow\left(x+3\right)\left(x+3\right)=-4\cdot\left(-9\right)\)

\(\Leftrightarrow\left(x+3\right)^2=36\)

\(\Leftrightarrow\orbr{\begin{cases}\left(x+3\right)^2=6^2\\\left(x+3\right)^2=\left(-6\right)^2\end{cases}}\)

\(\Leftrightarrow\orbr{\begin{cases}x+3=6\\x+3=-6\end{cases}}\)

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

Vậy ....

quy đồng

\(\left(x+3\right)^2=36\)

\(\left(x+3\right)^2-6^2=0\)

áp dụng định lí "  \(a^2-b^2=\left(a+b\right)\left(a-b\right)\) ta được

\(\left(x+3-6\right)\left(x+3+6\right)=0\)

\(x=3,x=-9\)

nhân chéo là đc:

3(x+2)=-4(x-5)

3x+6=-4x+20

3x+4x=20-6

7x     =14

 x      =2

Vậy x=2

ta có: \(A=\frac{4n+1}{2n+3}=\frac{4n+6-5}{2n+3}=\frac{2.\left(2n+3\right)-5}{2n+3}=2-\frac{5}{2n+3}\)

Để A thuộc Z

=> 5/2n+3 thuộc Z

=> 5 chia hết cho 2n +3

=> 2n+3 thuộc Ư(5)={1;-1;5;-5}

nếu 2n + 3 = 1 => 2n = -2 => n = -1 (Loại)

2n+3 = -1 => 2n=-4 => n = -2 (Loại)

2n+3 = 5 => 2n = 2 => n = 1 (TM)

2n+3 = -5 => 2n = -8 => n = -4 (Loại)

\(\Rightarrow n\ne1\) thì A là phân số ( n thuộc N)

Cảm ơn bạn CÔNG CHÚA ÔRI nhiều ạ

\(\frac{3}{4}+\frac{1}{5}:\frac{7}{10}\)

\(=\frac{3}{4}+\frac{2}{7}\)

\(=\frac{29}{28}\)

\(\frac{3}{4}\)+    \(\frac{1}{5}\):    \(\frac{7}{10}\)=    \(\frac{3}{4}\)+    \(\frac{2}{7}\)

                                         =    \(\frac{28}{28}\)=    1

b) \(\left(2,4.x-36\right)\div1\frac{5}{7}=-1\)

\(\left(2,4.x-36\right)=-1.\frac{12}{7}\)

\(2,4.x-36=-\frac{12}{7}\)

\(2,4.x=-\frac{12}{7}+36\)

\(2,4.x=\frac{240}{7}\)

\(x=\frac{240}{7}\div2,4\)

\(x=\frac{100}{7}\)

a) \(\frac{3}{x-5}=\frac{-4}{x+2}\)

\(\Rightarrow3.\left(x+2\right)=-4.\left(x-5\right)\)

\(\Rightarrow3x+6=-4x+20\)

\(\Rightarrow7x=14\)

\(\Rightarrow x=2\)

\(\frac{1}{2}x-\frac{1}{4}=\frac{-1}{2}\)

\(\frac{1}{2}x=\frac{-1}{2}+\frac{1}{4}\)

\(\frac{1}{2}x=\frac{-2+1}{4}\)

\(\frac{1}{2}x=\frac{-1}{4}\)

\(x=\frac{-1}{4}:\frac{1}{2}\)

\(x=\frac{-1}{4}.2\)

\(x=\frac{-1}{2}\)

Vậy .....................

\(\frac{1}{2}x-\frac{1}{4}=-\frac{1}{2}\)

\(\frac{1}{2}x=-\frac{1}{2}+\frac{1}{4}\)

\(\frac{1}{2}x=-\frac{2}{4}+\frac{1}{4}\)

\(\frac{1}{2}x=-\frac{1}{4}\)

\(x=-\frac{1}{4}:\frac{1}{2}\)

\(x=-\frac{1}{4}\cdot2\)

\(x=-\frac{1}{2}\)

Vậy .....