Câu 1 : 

a, \(\frac{3\left(2x+1\right)}{4}-\frac{5x+3}{6}=\frac{2x-1}{3}-\frac{3-x}{4}\)

\(\Leftrightarrow\frac{6x+3}{4}+\frac{3-x}{4}=\frac{2x-1}{3}+\frac{5x+3}{6}\)

\(\Leftrightarrow\frac{5x+6}{4}=\frac{9x+1}{6}\Leftrightarrow\frac{30x+36}{24}=\frac{36x+4}{24}\)

Khử mẫu : \(30x+36=36x+4\Leftrightarrow-6x=-32\Leftrightarrow x=\frac{32}{6}=\frac{16}{3}\)

tương tự 

\(\frac{19}{4}-\frac{2\left(3x-5\right)}{5}=\frac{3-2x}{10}-\frac{3x-1}{4}\)

\(< =>\frac{19.5}{20}-\frac{8\left(3x-5\right)}{20}=\frac{2\left(3-2x\right)}{20}-\frac{5\left(3x-1\right)}{20}\)

\(< =>95-24x+40=6-4x-15x+5\)

\(< =>-24x+135=-19x+11\)

\(< =>5x=135-11=124\)

\(< =>x=\frac{124}{5}\)

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

\(< =>\frac{\left(x-2\right).3.15}{30}+\frac{\left(x-3\right).5.10}{30}+\frac{\left(x-5\right).2.6}{30}=10-2-3-5\)

\(< =>\frac{\left(x-2\right).45+\left(x-3\right).50+\left(x-5\right).12}{30}=0\)

\(< =>45x-90+50x-150+12x-60=0\)

\(< =>107x-300=0< =>x=\frac{300}{107}\)

a) \(\left(2x-5\right)^2-\left(2x+3\right)\left(2x-3\right)=10\Leftrightarrow\left(4x^2-20x+25\right)-\left(4x^2-9\right)-10=0\)

\(\Leftrightarrow-20x+24=0\Leftrightarrow x=\frac{6}{5}\)

b) \(\left(4x-1\right)\left(x+2\right)-\left(2x+3\right)^2-5\left(x-1\right)=9\Leftrightarrow-10x-15=0\)

\(\Leftrightarrow x=\frac{-3}{2}\)

c) \(\left(x+1\right)^3-\left(x-1\right)^3-2=6\Leftrightarrow\left(x^3+3x^2+3x+1\right)-\left(x^3-3x^2+3x-1\right)-8=0\)

\(\Leftrightarrow6x^2-6=0\Leftrightarrow x=\pm1\)

d) \(\left(x+2\right)\left(x^2-2x+4\right)-\left(x+1\right)\left(x^2-x+1\right)-3\left(-x-2\right)=5\)

\(\Leftrightarrow\left(x^3+8\right)-\left(x^3+1\right)+3x+6=5\Leftrightarrow3x+8=0\Leftrightarrow x=\frac{-8}{3}\)

a) \(2x\left(x-3\right)-x\left(2x+1\right)-3\left(x+5\right)=11\)

\(\Rightarrow2x^2-6x-2x^2-x-3x-15=11\)

\(\Rightarrow-10x=26\Rightarrow x=-2,6\)

Vậy ...........

b) \(x\left(x-1\right)-\left(x^2+3x-5\right)-2\left(x+3\right)=17\)

\(\Rightarrow x^2-x-x^2-3x+5-2x-6=17\)

\(\Rightarrow-6x=18\Rightarrow x=-3\)

c) \(5x\left(x-7\right)-\left(5x+1\right)x-\left(x+3\right)2=13\)

\(\Rightarrow5x^2-35x-5x^2-x-2x-6=13\)

\(\Rightarrow-38x=19\Rightarrow x=-\frac{1}{2}\)

d) \(\left(2x^2-3x+5\right)-2x\left(x-3\right)+\left(x-1\right)\left(-2\right)=10\)

\(\Rightarrow2x^2-3x+5-2x^2+6x-2x+2=10\)

\(\Rightarrow x=3\)

giúp mik với

Cảm ơn bạn Diễm Quỳnh nhiều nha.

a: =>14x+20+5=6x-9-9x

=>14x+25=-3x-9

=>17x=-34

=>x=-2

b: =>\(2x^2-30x+2x-30=2x^2+10x-10x-50\)

=>-28x-30=-50

=>-28x=-20

=>x=20/28=5/7

c: =>2x+x^3-x=x^3+1

=>x=1

d: =>x^3-3x^2+3x-1-x(x^2+2x+1)=10x-2x^2-11x-22

=>x^3-3x^2+3x-1-x^3-2x^2-x=-2x^2-x-22

=>-5x^2+2x-1+2x^2+x+22=0

=>-3x^2+3x+21=0

=>x^2-x-7=0

=>\(x=\dfrac{1\pm\sqrt{29}}{2}\)

a) \(\frac{-2}{3}x+\frac{1}{5}=\frac{1}{10}\)

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

\(\Leftrightarrow\frac{-2}{3}x=\frac{-1}{10}\)

\(\Leftrightarrow x=\frac{-1}{10}\div\frac{-2}{3}\)

\(\Leftrightarrow x=\frac{3}{20}\)

ko có tên à

Giải như sau.

(1)+(2)⇔x2−2x+1+√x2−2x+5=y2+√y2+4⇔(x2−2x+5)+√x2−2x+5=y2+4+√y2+4⇔√y2+4=√x2−2x+5⇒x=3y(1)+(2)⇔x2−2x+1+x2−2x+5=y2+y2+4⇔(x2−2x+5)+x2−2x+5=y2+4+y2+4⇔y2+4=x2−2x+5⇒x=3y

⇔√y2+4=√x2−2x+5⇔y2+4=x2−2x+5, chỗ này do hàm số f(x)=t2+tf(x)=t2+t đồng biến ∀t≥0∀t≥0
Công việc còn lại là của bạn ! 

\(\left(x+6\right)\left(2x+1\right)=0\)

<=>  \(\orbr{\begin{cases}x+6=0\\2x+1=0\end{cases}}\)

<=>  \(\orbr{\begin{cases}x=-6\\x=-\frac{1}{2}\end{cases}}\)

Vậy....

hk tốt

^^

a,

(2x-3)-(x-5)=(x+2)-(x-1)

2x-3-x+5=x+2-x+1

x+2=3

x=1

b,

2(x-1)-5(x+2)=-10

2x-2-5x+10=-10

-3x+8=-10

-3x=-18

x=6

a) ( 2x - 3 ) - ( x - 5 ) = ( x + 2 ) - ( x - 1 )

    2x - 3 - x + 5        = x + 2 - x + 1

    ( 2x - x ) + ( 5 - 3 ) = ( x - x ) + ( 2 + 1 )

    x + 2                    = 3

    x                          = 3 - 2

    x                          = 1

b) 2( x - 1 ) - 5( x + 2 ) = -10

    2x - 2.1 - 5x + 5.2   = -10

    2x - 2 - 5x + 10       = -10

    ( 2x - 5x ) + ( 10 - 2 ) = -10

    -3x + 8                    = -10

    -3x                          = -10 - 8

    -3x                          = -18

       x                         = -18 : -3

       x                         = 6