Question

(2x-7)²-6(2x-7)(x-3)

 

 

Answer 1

a) (2x-7)^2 - 6(2x-7) (x-3) =0

=>(2x-7).(2x-7-6x+18)=0

=>(2x-7)(-4x+11)=0=>2x-7=0

=>x=72hoặc -4x+11=0

=>x=11/4

vậy x=7/2 hoặc x=11/4

Answer 2

Ta có: \(\left(2x-7\right)^2-6\left(2x-7\right)\left(x-3\right)=0\)

\(\Leftrightarrow\left(2x-7\right)^2-\left(2x-7\right)\left(6x-18\right)=0\)

\(\Leftrightarrow\left(2x-7\right)\left(2x-7-6x+18\right)=0\)

\(\Leftrightarrow\left(2x-7\right)\left(-4x+11\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}2x-7=0\\-4x+11=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}2x=7\\-4x=-11\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{7}{2}\\x=\dfrac{11}{4}\end{matrix}\right.\)

Vậy: \(S=\left\{\dfrac{7}{2};\dfrac{11}{4}\right\}\)

Answer 3

(2x-7)²- 6(2x-7)(x-3) = 0<=> (2x-7).(2x-7-6x+18)=0<=> (2x-7).(-4x+11)=0<=>       2x-7=0      <=> x =72hoặc     -4x+11=0   <=>x=11/4Vậy x = 7/2  hoặc  x = 11/4