\(\frac{5}{2}\left(x-\frac{3}{5}\right)-\frac{1}{10}=x-3\)

\(\Rightarrow\frac{5}{2}x-\frac{5}{2}\cdot\frac{3}{5}-\frac{1}{10}-x+3=0\)

\(\Rightarrow\frac{3}{2}x-\frac{3}{2}-\frac{1}{10}+3=0\)

\(\Rightarrow\frac{3}{2}x+\frac{7}{5}=0\)\(\Rightarrow\frac{3}{2}x=-\frac{7}{5}\)\(\Rightarrow x=-\frac{14}{15}\)

Bài 1 :

Ta có : 

\(120^o+y=180\) ( 2 góc kề bù )

\(y=60^o\)

Mà x, y là 2 góc đối đỉnh 

\(\Rightarrow x=60^o\) ( 2 góc đối đỉnh = nhau )

Lại có : 

\(\hept{\begin{cases}t=60^o\left(\text{đ}^2\right)\\60+z=180\left(\text{kề bù}\right)\end{cases}}\)

\(\Rightarrow z=120^o\)

Vậy ....

TL

z=120^o

HT

TL:

Đây nhé

~~HT~

!!!

\(2a=3b\Leftrightarrow\frac{a}{15}=\frac{b}{10},\frac{b}{5}=\frac{c}{4}\Leftrightarrow\frac{b}{10}=\frac{c}{8}\)

suy ra \(\frac{a}{15}=\frac{b}{10}=\frac{c}{8}\).

Áp dụng tính chất dãy tỉ số bằng nhau ta có: 

\(\frac{a}{15}=\frac{b}{10}=\frac{c}{8}=\frac{a-b+c}{15-10+8}=\frac{-21}{13}\)

\(\Leftrightarrow\hept{\begin{cases}a=-\frac{21}{13}.15=-\frac{315}{13}\\b=-\frac{21}{13}.10=-\frac{210}{13}\\c=-\frac{21}{13}.8=-\frac{168}{13}\end{cases}}\)

Từ \(2a=3b\)\(\Leftrightarrow\)\(\frac{a}{3}=\frac{b}{2}\)

Từ \(\frac{a}{3}=\frac{b}{2}=\frac{a}{3}.\frac{1}{5}=\frac{b}{2}.\frac{1}{5}\)\(\Rightarrow\)\(\frac{a}{15}=\frac{b}{10}\)( 1 )

Từ \(\frac{b}{5}=\frac{c}{4}=\frac{b}{5}.\frac{1}{2}=\frac{c}{4}.\frac{1}{2}\)\(\Rightarrow\)\(\frac{b}{10}=\frac{c}{8}\)( 2 )

Từ ( 1 ) và ( 2 ) suy ra : \(\frac{a}{15}=\frac{b}{10}=\frac{c}{8}\)

Áp dụng t/c dãy tỉ số bằng nhau ta có :

\(\frac{a}{15}=\frac{b}{10}=\frac{c}{8}=\frac{a-b+c}{15-10+8}=\frac{-21}{13}\)

\(\Rightarrow\hept{\begin{cases}\frac{a}{15}=-\frac{21}{13}\\\frac{b}{10}=-\frac{21}{12}\\\frac{c}{8}=-\frac{21}{13}\end{cases}}\)\(\Rightarrow\hept{\begin{cases}a=-\frac{315}{13}\\b=-\frac{210}{13}\\c=-\frac{168}{13}\end{cases}}\)

TL

x = 35/2,

y = 99/2,

z = 66;

HT

\(\text{( 2x-3²)-13=36}\)

\(\text{=) 2x-9-13=36}\)

\(\text{=)2x=36+13+9}\)

\(\text{=)2x=58}\)

\(\text{=)x=29}\)

~ Are you ok , Học tốt ~ 

Giang ơi nó là 2 + 3 TẤT CẢ MŨ 2 cơ mà

( 2x - 3 )² = 36 + 13

( 2x - 3 )² = 49

( 2x - 3 )² = 7²

=> 2x - 3 = 7

2x = 7 + 3 

2x = 10

x = 10 : 2 

x = 5

HT