Đáp án + Giải thích các bước giải:
Bài `1:`
`a//[25+(-15)]+(-29)`
`=10+(-29)`
`=-19`
`b//512-(-88)-400-125`
`=512+88-(400+125)`
`=600-525`
`=75`
`c//-(310)+(-210)-907+107`
`=-(310+210)-(907-107)`
`=-520-800`
`=-1320`
`d//2004-1975-2000+2005`
`=(2004-2000)+(2005-1975)`
`=4+30`
`=34`
Bài `2:`
`a//-x+8=-17-30`
`->-x=-17-30-8`
`->x=17+30+8`
`->x=55`
`b//35-x=37`
`->x=35-37`
`->x=-2`
`c//(-19-x)+23=-20`
`→-19-x+23=-20`
`→-x=-20+19-23`
`→-x=-24`
`->x=24`
`d//(x-45):2=-17`
`→x-45=-17.2`
`→x-45=-34`
`->x=-34+45`
`->x=11`
Bài `3:`
`a//|x+3|=15`
`→x+3=±15`
`→` \(\left[ \begin{array}{l}x=12\\x=-18\end{array} \right.\)
Vậy `x∈{12;-18}`
`b//|x-7|+13=25`
`→|x-7|=12`
`→x-7=±12`
`→` \(\left[ \begin{array}{l}x=19\\x=-5\end{array} \right.\)
Vậy `x∈{19;-5}`
`c//|x-3|-16=-4`
`→|x-3|=12`
`→x-3=±12`
`→` \(\left[ \begin{array}{l}x=15\\x=-9\end{array} \right.\)
Vậy `x∈{15;-9}`
`d//26-|x+9|=-13`
`->|x+9|=26-(-13)`
`->|x+9|=39`
`->x+9=±39`
`→` \(\left[ \begin{array}{l}x=30\\x=-48\end{array} \right.\)
Vậy `x∈{30;-48}`
