i) `4x^6=\frac{9}{25}x^4`
`<=> 100x^6=9x^4`
`<=> 100x^6-9x^4=0`
`<=> x^4(100x^2-9)=0`
`<=>`\(\left[ \begin{array}{l}x=0\\x=±\frac{3}{10}\end{array} \right.\)
Vậy: ...
j) `2(2x-3)^6=1/2(2x-3)^4`
`<=> 2(2x-3)^6=\frac{(2x-3)^4}{2}`
`<=> 4(2x-3)^6-(2x-3)^4=0`
`<=> (2x-3)^4.[4(2x-3)^2-1]=0`
`<=> x∈{\frac{3}{2};\frac{7}{4}\frac{5}{4}}`
Vậy: ...