Question

Tìm x biết:

(x-3)^2+(x+5)(2-x)=0

x^2+2x-8=0

 

 

 

Answer 1

1)

\(\left(x-3\right)^2+\left(x+5\right)\left(2-x\right)=-\left(9x-19\right)\)

\(-\left(9x-19\right)=0\)

\(9x=-19\)

\(\Rightarrow x=\frac{19}{9}=2\frac{1}{9}\)

Answer 2

\(x_1+x_2=-\frac{b}{a}=-2\)

\(x_1.x_2=\frac{c}{a}=-8\)

\(x\in-4;2\)