Đáp án + Giải thích các bước giải:
a)
`x+25%.x=|-10|`
`=>1x+1/4.x=10`
`=>x(1/4+1)=10`
`=>x(1/4+4/4)=10`
`=>x. 5/4=10`
`=>x=10:5/4`
`=>x=10. 4/5`
`=>x=8`
b)
`|2x-1|=3^2019:3^2017`
`=>|2x-1|=3^2`
`=>|2x-1|=9`
`=>` \(\left[ \begin{array}{l}2x-1=9\\2x-1=-9\end{array} \right.\)
`=>` \(\left[ \begin{array}{l}2x=9+1\\2x=-9+1\end{array} \right.\)
`=>` \(\left[ \begin{array}{l}2x=10\\2x=-8\end{array} \right.\)
`=>` \(\left[ \begin{array}{l}x=10:2\\x=-8:2\end{array} \right.\)
`=>` \(\left[ \begin{array}{l}x=5\\x=-4\end{array} \right.\)
Vậy `x∈{5;-4}`
