Đáp án:
Giải thích các bước giải:
Bài `1:`
`a)(-14).0=0`
`b)6.(-12)=-72`
`c)(-7).(-8)=56`
`d)(-4).(-5).(-6)=-120`
`e)2008-(2001+2007)`
`=2008-4008`
`=-2000`
`f)(-1999+2001)-2009`
`=2-2009`
`=-2007`
`g)1-{2-[3-(4-5)]}`
`=1-{2-3-(-1)}`
`=1-{2-3+1}`
`=2`
`h)(-4).[29-3(-19-25)]+489`
`=(-4).[29-3.(-44)]+489`
`=(-4).161+489`
`=-644+489`
`=-155`
Bài `4:`
`a)3-(2+|x|)=0`
`→3-2-|x|=0`
`→1-|x|=0`
`→|x|=1`
`→` \(\left[ \begin{array}{l}x=1\\x=-1\end{array} \right.\)
Vậy `x∈{1;-1}`
`b)|x-1|=2`
`→` \(\left[ \begin{array}{l}x-1=2\\x-1=-2\end{array} \right.\)
`→` \(\left[ \begin{array}{l}x=3\\x=-1\end{array} \right.\)
Vậy `x∈{3;-1}`
`c)24-[x+(-34)]=56`
`→24-x+34=56`
`→58-x=56`
`→x=2`
Vậy `x=2`
`d)1-(4x+13)=3-x`
`→1-4x-13=3-x`
`→-4x+x=3-1+13`
`→-3x=15`
`→x=-5`
Vậy `x=-5`
