Đáp án+Giải thích các bước giải:
`a)2/3x+1/2=1/10`
`→2/3x=1/10-1/2`
`→2/3x=-2/5`
`→x=-2/5:2/3`
`→x=-2/5.(3)/2`
`\to x=-3/5`
Vậy `x=-3/5`
`b)`
`(3(4)/5-2x).1(1)/3=5(5)/7`
`→(19/5-2x).(4)/3=(40)/7`
`→19/5-2x=40/7:4/3`
`→19/5-2x=30/7`
`→2x=19/5-30/7`
`→2x=133/35-150/35`
`→2x=(133-150)/35`
`→2x=-17/35`
`→x=-17/35:2`
`→x=-17/70`
Vậy `x=-17/70`
`c)`
`|x-1|+0,225=3`
`→|x-1|+9/40=3`
`→|x-1|=3-9/40`
`→|x-1|=111/40`
\(→\left[ \begin{array}{l}x-1=\dfrac{111}{40}\\x-1=-\dfrac{111}{40}\end{array} \right.\)
\(→\left[ \begin{array}{l}x=\dfrac{111}{40}+1\\x=-\dfrac{111}{40}+1\end{array} \right.\)
\(→\left[ \begin{array}{l}x=\dfrac{151}{40}\\x=-\dfrac{71}{40}\end{array} \right.\)
Vậy `x∈\{151/40;-71/40\}`
