Question

giúp vớiiii

Answer 1

a: \(A=1\)

\(\Leftrightarrow19-2x^2=1\)

\(\Leftrightarrow2x^2=18\)

\(\Leftrightarrow x^2=9\)

=>x=3 hoặc x=-3

b: B=0

=>(x+2)(x²-4)=0

=>(x+2)²(x-2)=0

=>x=-2 hoặc x=2

Answer 2

\(A=19-2x^2=1\)

\(18-2x^2=0\)

\(x^2=9\)

\(\Rightarrow\left[{}\begin{matrix}x=3\\x=-3\end{matrix}\right.\)

Answer 3

\(B=\left(x+2\right)\left(x^2-4\right)=0\)

\(=\left(x+2\right)\left(x+2\right)\left(x-2\right)=0\)

\(=\left(x+2\right)^2\left(x-2\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}x=2\\x=-2\end{matrix}\right.\)