Question

cần gaaps ạ hứa k

Answer 1

f) ... \(\Leftrightarrow x^3+3x^2+3x+1+x^3-3x^2+3x-1=x^2-1+4\) 

\(\Leftrightarrow2x^3+6x=x^2-3\)  \(\Leftrightarrow\left(2x+1\right)\left(x^2+3\right)=0\)  \(\Leftrightarrow2x+1=0\)  \(\Leftrightarrow x=-\dfrac{1}{2}\)

g) ... \(\Leftrightarrow x\left(x^2-6x+9\right)=0\)  \(\Leftrightarrow x\left(x-3\right)^2=0\Leftrightarrow\left[{}\begin{matrix}x=0\\x=3\end{matrix}\right.\)

h) ... \(\Leftrightarrow x^2=\dfrac{25}{9}\Leftrightarrow x=\pm\dfrac{5}{3}\)

i)  ... \(\Leftrightarrow x^2-4x+4-\left(x^2-x+3x-3\right)=-7\)  \(\Leftrightarrow-6x+14=0\) \(\Leftrightarrow x=\dfrac{7}{3}\)

k) ... \(\Leftrightarrow\) 2x - 1 = 0 và x + 5 = 0 => PTVN