Question

x.(x+2)+x-2=0

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

(x+2).(x+3)-(x-2).(x+5)=o

Answer 1

a)x.(x+2)+x-2=0

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

\(\Leftrightarrow x^2+3x-2=0\)

\(\Delta=3^2-\left(-4\left(1.2\right)\right)=17\)

\(x_{1,2}=\frac{-3\pm\sqrt{17}}{2}\)

 

Answer 2

mk nghĩ câu a sai đề

Answer 3

b)5x.(x-3)-x+3=0

\(\Leftrightarrow5x\left(x-3\right)-\left(x-3\right)=0\)

\(\Leftrightarrow\left(5x-1\right)\left(x-3\right)=0\)

\(\Leftrightarrow\left[\begin{array}{nghiempt}5x-1=0\\x-3=0\end{array}\right.\)

\(\Leftrightarrow\left[\begin{array}{nghiempt}x=\frac{1}{5}\\x=3\end{array}\right.\)

 

Answer 4

c)(x+2).(x+3)-(x-2).(x+5)=o

<=>x²+5x+6-x²-3x+10=0

<=>2x+16=0

<=>2x=-16

<=>x=-8