Question

tìm x:

12x² - 4(3x - 5)= 10x - 17

Answer 1

\(\Leftrightarrow12x^2-12x+20-10x+17=0\)

\(\Leftrightarrow12x^2-22x+37=0\)

\(\Leftrightarrow12\left(x^2-\frac{11}{6}x+\frac{37}{12}\right)=0\)

\(\Leftrightarrow12\left(x^2-2x\cdot\frac{11}{12}+\frac{121}{144}-\frac{121}{144}+\frac{37}{12}\right)=0\)

\(\Leftrightarrow12\left[\left(x-\frac{11}{12}\right)^2+\frac{323}{144}\right]=0\)

\(\Leftrightarrow12\left(x-\frac{11}{12}\right)^2+\frac{323}{12}=0\) ( vô nghiệm )