a)$-17+15-34-(-18)=-17+15-34+18=(-17-34)+(15+18)=-51+33=-18$
b)$-25+(13-27)-(-7-10)=-15+13-27+7+10=(-15+10)+(13+7)-27=-12$
c)$-2020-(158-2020)=-2020-158+2020=(-2020+2020)-158=-158$
d)$3.(-4)-12:(-2)=-12-(-6)=12+6=18$
e)$-125.34-34.(-25)=34(-125-(-25))=34(-125+25)=34.-100=-3400$
g)$-5-(17-42).-2-|3-7|=-5-(-25).-2-|-4|=-5+25.-2-4=20.(-6).-120$
h)$-2.358+2.256=-2.(256+2)+2.256=-2.256+-2.2+2.256=-4$
i)$-|3-17|-|50-47|.(-2)=-14-3.(-2)=-20$
Bài 2
a)$|x-3|-16=-4$
TH1:-x+3-16=-4
=>-x=-4+16-3=9
=>x=-9
TH2:$x-3-14=-4$
=>x=3+14-4=13
b)|5-x|.2+3=-5
TH1: (-5+x).2+3=-5
=>-10+2x+3=-5
=>2x=-5-3+10=2
=>x=1
TH2: (5-x).2+3=-5
=>2.5-2x+3=-5
=>-2x=-5-3-10
=>2x=-18
=>x=-18/2=-9
c)$3-x+17=2x+29$
=>$-x-2x=-3-17+29$
=>$-3x=9$
=>x=9/-3=-3
d)-2+3x-3-5x=-17-4
=>+3x-5x=2+3-17-4
=>-2x=-26
=>x=-16/-2=8
e)4-5x=3+(-7-5).2
=>4-5x=3+(-12).2
=>4-5x=3+-24
=>-5x=-4+3+(-24)
=>-5x=-25
=>x=-25/-5=5