(-35)+18-13=
tính
3/17 + -5/13 + -18/35 + 14/17 + 17/-35 + -8/13
\(\frac{3}{17}+\frac{-5}{13}+\frac{-18}{35}+\frac{14}{17}+\frac{17}{-35}+\frac{-8}{13}\)
\(=\frac{3}{17}+\frac{-5}{13}+\frac{-18}{35}+\frac{14}{17}+\frac{-17}{35}+\frac{-8}{13}\)
\(=\left(\frac{3}{17}+\frac{14}{17}\right)+\left(\frac{-5}{13}+\frac{-8}{13}\right)+\left(\frac{-18}{35}+\frac{-17}{35}\right)\)
\(=\frac{17}{17}+\frac{-13}{13}+\frac{-35}{35}\)
\(=1+\left(-1\right)+\left(-1\right)\)
\(=-1\)
\(\frac{3}{17}+\frac{-5}{13}+\frac{-18}{35}+\frac{14}{17}+\frac{17}{-35}+\frac{-8}{13}\)
= \(\frac{3}{17}+\frac{-5}{13}+\frac{-18}{35}+\frac{14}{17}+\frac{-17}{35}+\frac{-8}{13}\)
= \(\left(\frac{3}{17}+\frac{14}{17}\right)+\left(\frac{-5}{13}+\frac{-8}{13}\right)+\frac{-18}{35}\)
= 1+(-1)+\(\frac{-18}{35}\)
= 0+\(\frac{-18}{35}\)
= \(\frac{-18}{35}\)
\(\frac{3}{17}-\frac{5}{13}-\frac{18}{35}+\frac{14}{17}-\frac{17}{35}-\frac{8}{13}=\left(\frac{3}{17}+\frac{14}{17}\right)-\left(\frac{5}{13}+\frac{8}{13}\right)-\left(\frac{18}{35}+\frac{17}{35}\right)\)
\(=1-1-1\)
=-1
Tính nhanh :
3/17 - 5/13 - 18/35 + 14/17 + 17/-35 - 8/13
3/17 - 5/13 - 18/35 + 14/17 + 17/-35 - 8/13
=(3/17+14/17)+(-5/13-8/13)+(-18/35+17/35)
=1+(-1)+(-1/35)
=-1/35
Chúc bn học tốt
\(\frac{3}{17}-\frac{5}{13}-\frac{18}{35}+\frac{14}{17}\)\(+\frac{17}{-35}-\frac{8}{13}\)
\(=\left(\frac{3}{17}+\frac{14}{17}\right)\)\(-\left(\frac{18}{35}-\frac{-17}{35}\right)\)\(-\left(\frac{5}{13}+\frac{8}{13}\right)\)
\(=1-1-1\)\(=0\)
a) 214 + [120-(214+120)]
b) (-321)-[(-321+35) -235 ]
c) (18+29)+(158-29-18)
d) (13-135+49)-(13+49)
g)18 . (-24) + 35 . 42 -18 . 76 + 35 . (-142)
h) 104 : (-13) - [ 56 - 220 : ( -4 )]
i)1010: {2500:[ 550 - (4 . 53 - 23 . 25) ]}
j) (72 + 32 . 42 )+(-145 ) + 45 -20230 + 12023
a, 18.(-24) + 35.42 - 18.76 + 35.(-142)
= [ 18.(-24) - 18.76] + (35.42 + 35(-142)]
= -18.[ 24 + 76] - 35.( 142 - 42)
= -18.100 - 35. 100
= - 100.(18 + 35)
= - 100. 53
= - 5300
h, 104 : (-13) - [56 - 220 : (-4)]
= 104 : (-13) - [ 56 + 55]
= -8 - 111
= - 119
j; 1010 : {2500 : [550 - (4.53 - 23.25)]}
= 1010 : {2500 : [550 - (212 - 575)]}
= 1010 : {2500 : [550 + 363]
= 1010 : { 2500 : 913}
= 1010 : \(\dfrac{2500}{913}\)
= 1010 x \(\dfrac{913}{2500}\)
= 368,852
2. Tìm x biết : a) 13.(25-4x)=13 b) (2x-4).15=0 c) (x-35)-115=0 d) x-36:18=12 e) (x-36):18=12
a: =>25-4x=1
=>4x=24
hay x=6
b: =>2x-4=0
hay x=2
c: =>x-35=115
hay x=150
d: =>x-2=12
hay x=14
e: =>x-36=216
hay x=252
a,9/4-[-11}/-4
b, 7/8-3/-8-1/8
c,-5/21-25/21-[-1]/21
d, 18/24-35/-10
e, 3/7-11/14-19/28
g, 5/-{-2}/3-1/12
h, 3/17-{-5}/13-{-18}/35-14/17-17/{-35}-{-8}/13
a; \(\dfrac{9}{4}\) - \(\dfrac{-11}{4}\)
= \(\dfrac{9}{4}\) + \(\dfrac{11}{4}\)
= \(\dfrac{20}{4}\)
= 5
b; \(\dfrac{7}{8}\) - \(\dfrac{3}{-8}\) - \(\dfrac{1}{8}\)
= \(\dfrac{7}{8}\) + \(\dfrac{3}{8}\) - \(\dfrac{1}{8}\)
= \(\dfrac{7+3-1}{8}\)
= \(\dfrac{9}{8}\)
c; \(\dfrac{-5}{21}\) - \(\dfrac{25}{21}\) - \(\dfrac{-1}{21}\)
= \(\dfrac{-5}{21}\) - \(\dfrac{25}{21}\) + \(\dfrac{1}{21}\)
= \(\dfrac{-5-25+1}{21}\)
= \(\dfrac{-29}{21}\)
28) 15/12+5/13-3/12-18/13
29) 13/25+6/41-38/25+35/41-1/2
30
Tính bằng cách hợp lí :
35 . 11 + 65 . 18 + 35 . 13 + 65 . 6
co gi do sai sai hay sao
35.11+65.18+35.13+65.6
=35(11+13)+65(18+6)
=35.24+65.24
=24(35+65)
=24.100
=2400
=35.(11+13)+65.(18+6)
=35.24+65.24
=(35+65).24
=100.24
=2400
hok tốt
1:tính nhanh
A=-3^17[2^3+3^17]
B=3^17+-5^13+-18^35+14^17+17^-35