Đáp án:
`↓↓`
Giải thích các bước giải:
`d) |(2x+1)/5|.(1/3x-5/4)=0`
`=>` \(\left[ \begin{array}{l}\dfrac{2x+1}{5}=0 \\ \dfrac{1}{3}x-\dfrac{5}{4}=0\end{array} \right.\)
`=>` \(\left[ \begin{array}{l}2x+1=0\\\dfrac{1}{3}x=\dfrac{5}{4}\end{array} \right.\)
`=>` \(\left[ \begin{array}{l}x=-\dfrac{1}{2}\\x=\dfrac{15}{4}\end{array} \right.\)
`f) x(2x-1)-x^2(x+2)+x^3-x+3=0`
`=> 2x^2-x-x^3-2x^2+x^3-x+3=0`
`=> 3-2x=0`
`=> x=3/2`