\(x^2=\left(x-1\right)\left(3x-2\right)\)
\(\Leftrightarrow x^2=3x^2-5x+3\)
\(\Leftrightarrow2x^2-5x=-3\)
\(x\left(2x-5\right)=-3\)
->Lập bảng->tìm x
Ta có: \(x^2=\left(x-1\right)\left(3x-2\right)\)
\(=3x^2-5x+2\)
\(\Rightarrow3x^2-5x+2-x^2=0\)
\(\Rightarrow2x^2-5x+2=0\)
\(\Rightarrow2\left(x^2-\frac{5}{2}x+1\right)=0\)
\(\Rightarrow x^2-\frac{5}{2}x+1=0\)
\(\Rightarrow x^2-2.\frac{5}{4}x+\left(\frac{5}{4}\right)^2-\frac{9}{16}=0\)
\(\Rightarrow\left(x-\frac{5}{4}\right)^2=\frac{9}{16}\)
\(\Rightarrow x-\frac{5}{4}=\frac{3}{4}\)hoặc \(x-\frac{5}{4}=-\frac{3}{4}\)
\(\Rightarrow x=2\) hoặc \(x=\frac{1}{2}\)
Nhớ vs kb với tớ nhia mn! > < ))
x^2 = ( x - 1 ) ( 3x - 2 )
x^2 = 3x^2 - 5x + 2
x^2 - 3x^2 + 5x - 2 = 0
-2x^2 + 5x - 2 = 0
-2x^2 + 4x + x - 2 = 0
-2x ( x - 2 ) + 1 ( x - 2 ) = 0
( x - 2 ) ( -2x + 1 ) = 0
x - 2 = 0 hoặc -2x + 1 = 0
x = 0 + 2 hoặc -2x = 0 - 1
x = 2 hoặc -2x = -1
x = 2 hoặc x = -1 : -2
x = 2 hoặc x = 1/2
