Question

a, x\(^2\)-5x+6=0

Answer 1

\(x^2-5x+6=0\\ a=1;b=-5;c=6\\ =>\Delta=\left(-5\right)^2-4.1.6=25-24=1>0\)

\(=> Phương\ trình\ có\ 2\ nghiệm\ phân\ biệt:\)

\(x_1=\dfrac{-\left(-5\right)+\sqrt{1}}{2.1}=3;x_2=\dfrac{-\left(-5\right)-\sqrt{1}}{2.1}=2\)

Answer 2

\(x^2-5x+6=0\\ < =>\left(x^2-2x\right)-\left(3x-6\right)=0\\ < =>x\left(x-2\right)-3\left(x-2\right)=0\\ < =>\left(x-2\right)\left(x-3\right)=0\\ =>\left[{}\begin{matrix}x-2=0\\x-3=0\end{matrix}\right.< =>\left[{}\begin{matrix}x=2\\x=3\end{matrix}\right.=>S=\left\{2;3\right\}\)

Answer 3