a: \(\Leftrightarrow2x^2+6x-3x-9=0\)
=>(x+3)(2x-3)=0
=>x=3/2 hoặc x=-3
b: \(\Leftrightarrow6x\left(1-2x\right)=0\)
=>x=0 hoặc 1-2x=0
=>x=0 hoặc x=1/2
c: \(\Leftrightarrow8x^2=1\)
\(\Leftrightarrow x^2=\dfrac{2}{16}\)
hay \(x\in\left\{\dfrac{\sqrt{2}}{4};-\dfrac{\sqrt{2}}{4}\right\}\)
d: \(\Leftrightarrow x^4-9x^2+2x^2-18=0\)
\(\Leftrightarrow x^2-9=0\)
=>x=3 hoặc x=-3