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

\(\Leftrightarrow3x^2+6x-3x^2-36=0\)

\(\Leftrightarrow6x-36=0\)

\(\Leftrightarrow x=6\)

3x^2-3x(-2+x)=36

3x^2 + 6x - 3x^2 = 36

6x = 36

x= 6

Bài 3:

1. \(\left(x-1\right)\left(x+2\right)+5x-5=0\)

\(\Rightarrow\left(x-1\right)\left(x+2\right)+5\left(x-1\right)=0\)

\(\Rightarrow\left(x-1\right)\left(x+2+5\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}x-1=0\\x+7=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=1\\x=-7\end{matrix}\right.\)

Vậy.......................

2. \(\left(3x+5\right)\left(x-3\right)-6x-10=0\)

\(\Rightarrow\left(3x+5\right)\left(x-3\right)-2\left(3x+5\right)=0\)

\(\Rightarrow\left(3x+5\right)\left(x-3-2\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}3x+5=0\\x-5=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=-\dfrac{5}{3}\\x=5\end{matrix}\right.\)

Vậy........................

3. \(\left(x-2\right)\left(2x+3\right)-7x^2+14x=0\)

\(\Rightarrow\left(x-2\right)\left(2x+3\right)-7x\left(x-2\right)=0\)

\(\Rightarrow\left(x-2\right)\left(2x+3-7x\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}x-2=0\\-5x+3=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=2\\x=\dfrac{3}{5}\end{matrix}\right.\)

Vậy............................

4, 5 tương tự nhé bn!

bài 3

1 (x-1)(x+2)+5x-5=0

=>(x-1)(x+2)+(5x-5)=o

=>(x-1)(x+2)+5(x-1)=0

=>(x-1)(x+2+5)=0

=>(x-1)(x+7)=0

=>\(\left[{}\begin{matrix}x-1=0\\x+7=0\end{matrix}\right.\) =>\(\left[{}\begin{matrix}x=1\\x=-7\end{matrix}\right.\)

vậy x=1 hoặc x=-7

2. (3x+5)(x-3)-6x-10=0

=>(3x+5)(x-3)-(6x+10)=0

=>(3x+5)(x-3)-2(3x+5)=0

=>(3x+5)(x-3-2)=0

=>(3x+5)(x-5)=0

=>\(\left[{}\begin{matrix}3x+5=0\\x-5=0\end{matrix}\right.\)=>\(\left[{}\begin{matrix}x=-\dfrac{5}{3}\\x=5\end{matrix}\right.\)

\(3x^2-3x=36\)

\(\Leftrightarrow x^2-x=12\)

\(\Leftrightarrow x^2-x-12=0\)

\(\Leftrightarrow\left(x^2-4x\right)+\left(3x-12\right)=0\)

\(\Leftrightarrow\left(x-4\right)\left(x+3\right)=0\)

Dễ rồi tự làm

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

\(=3x^2+6x-3x=36\)

\(=3x^2-3x=36\)

\(=3x\left(x-3\right)=36\)

\(\Leftrightarrow\)\(\orbr{\begin{cases}3x=36\\x-3=36\end{cases}\Leftrightarrow\orbr{\begin{cases}x=36:3=12\\x=36+3=39\end{cases}}}\)

Vậy S = { 12 ; 39 }

sai rồi nhs, bn giải pt cho 3x²-3x=36 =3x(x-3)=36 chỗ đó sai rồi

\(3x^{2}+3x-36\)

\(=x^{2}+x-12\)

\(=x^{2}-3x+4x-12\)

\(=x(x-3)+4(x-3)\)

\(=(x+4)(x-3)\)

\(3x^2+3x-36=3\left(x^2+x-12\right)=3\left(x+4\right)\left(x-3\right)\)

A=\(\dfrac{3x^3-14x^2+3x+36}{3x^3-19x^2+33x-9}\)

=>A \(=\dfrac{\left(x-3\right)\left(3x^2-5x-12\right)}{\left(x-3\right)\left(3x^2-10x+3\right)}\)

=>A=\(\dfrac{\left(x-3\right)^2\left(3x+4\right)}{\left(x-3\right)^2\left(3x-1\right)}\)

=>A=\(\dfrac{3x+4}{3x-1}\)

bạn viết rõ ràng ra được ko

mình sẽ giúp bạn

căn  3x-5 + căn 7-3x = 9x mũ 2 -36+38

huhu binhphuong len thi to  qua

a)3x+10-2x>-11
3x - 2x > -10-11
1x > -21
x > -21
b) 3x2 - 6x + 3x2 < 36
-6x < 36
x < -6

a) \(3x+2\left(5-x\right)=-11\)

\(\Leftrightarrow3x+10-2x=-11\)

\(\Leftrightarrow x=-21\)

b) \(3x^2-3x\left(x-2\right)=36\)

\(\Leftrightarrow3x^2-3x^2+6x=36\)

\(\Rightarrow x=6\)

?????????????????????????????????????

3x + 2( 5 - x ) = -11

<=> 3x + 10 - 2x = -11

<=> x + 10 = -11

<=> x = -21

3x² - 3x( x - 2 ) = 36

<=> 3x² - 3x² + 6x = 36

<=> 6x = 36

<=> x = 6