=18+5=23

1: =5/8*17/13*7/17*8/3*6

=5/3*7/13*6

=5*7*2/13=70/13

2: =-7/9(24/19-1)

=-7/9*5/19

=-35/171

3: =-3/8(7/6-9/6)

=-3/8*(-2/6)

=3/8*1/3=1/8

\(a,18.17-3.6.7\)

\(=18.17-18.7\)

\(=18.\left(17-7\right)\)

\(=18.10\)

\(=180\)

\(b,54-6.\left(17+9\right)\)

\(=54-6.17+6.9\)

\(=54-102+54\)

\(=\left(54+54\right)-102\)

\(=108-102\)

\(=6\)

\(c,33.\left(17-5\right)-17.\left(33-5\right)\)

\(=33.17-33.5-17.33-17.5\)

\(=\left(33.17-17.33\right)-\left[5\left(33-17\right)\right]\)

\(=0-5.16\)

\(=-80\)

a) \(18.17-3.6.7\)

\(=18.17-18.7\)

\(=18.\left(17-7\right)\)

\(=18.10\)

\(=180\)

b) \(54-6.\left(17+9\right)\)

\(=54-102-54\)

\(=-102\)

c) \(33.\left(17-5\right)-17.\left(33-5\right)\)

\(=561-165-561+85\)

\(=-80\)

a , 18 . 17 - 3 . 6 . 7

= 18 .17 - 18 . 7

= 18 . ( 17 - 7 )

= 18 . 10

= 180

b , 54 - 6 . ( 17 + 9 )

= 54 - 6 . 17 + 6 . 9

= 54 - 102 + 54

= ( 54 - 54 ) - 102

= 0 - 102

= - 102

c , 33 . ( 17 - 5 ) - 17 . ( 33 - 5 )

= 33 . 17 - 33 . 5 - 17 . 33 - 17 .5

= 0 - 5 . 16

= 0 - 80

= - 80

Giúp tớ với tớ cần gấp

a: \(=\dfrac{-5}{7}-\dfrac{2}{7}+\dfrac{3}{4}+\dfrac{1}{4}-\dfrac{1}{5}=-\dfrac{1}{5}\)

b: \(=\dfrac{-3}{31}-\dfrac{28}{31}+\dfrac{-6}{17}-\dfrac{11}{17}+\dfrac{1}{29}-\dfrac{1}{5}=\dfrac{-24}{145}\)

a) \(=\left(\left(-\frac{1}{4}-\frac{5}{3}\right)+\frac{7}{33}\right)-\left(-\frac{15}{12}+\frac{6}{11}-\frac{48}{49}\right)\)

\(=\left(-\frac{23}{12}+\frac{7}{33}\right)+\frac{15}{12}-\frac{6}{11}+\frac{48}{49}\)

\(=\left(-\frac{23}{12}+\frac{15}{12}\right)+\left(\frac{9}{33}-\frac{6}{11}\right)+\frac{48}{49}\)

\(=-\frac{2}{3}-\frac{3}{11}+\frac{48}{49}\)

\(=\frac{65}{1617}\)

b) \(=\frac{11}{125}+\left(-\frac{17}{18}+\frac{4}{9}\right)+\left(-\frac{5}{7}+\frac{17}{14}\right)\)

\(=\frac{11}{125}-\frac{1}{2}+\frac{1}{2}\)

\(=\frac{11}{125}\)

tính từng cái là đc

cau a em

\(\frac{5}{3}+-\frac{2}{7}-\left(-\frac{1}{2}\right)=\frac{29}{21}-\left(-\frac{1}{2}\right)=\frac{79}{42}\)

b . tương tự 

giúp tớ nhé

tớ bị trừ 590 điểm

cảm ơn trước 

a) 18.17 - 3.6.7

= 18.17-18.7

=18.( 17 - 7 )

= 18 . 10

= 180

b) 54 - 6.( 17 + 9) 

= 6.9 - 6 . 26

= 6.( 9 - 26 ) 

= 6 . ( - 17 ) 

= -102

c) 33.(17 - 5 ) - 17.(33-5)

= 33.17 - 33 .3  - 17.33 -  17 . 5 

= 33.17 + ( -33 ) .3 + ( - 17) .33 + ( -17) .5

= 33.17 + ( - 17) . 33 + 33 . ( - 3) + ( -17 ) .5

= 33. [ 17 + ( -17 ) + ( - 3 )] + (-17) . 5

= 33 . ( - 3 ) + ( -17 ) .5

= -99 + ( - 85)

= -184

a) 18 . 17 - 3 . 6 . 7                   b) 54 - 6 . ( 17 + 9 )                             

= 306      - 126                           = 48  . 26                                            

= 180                                        = 1248

,mk giúp đc từng đó nha

a: \(A=\dfrac{5}{7}-\dfrac{2}{7}+\dfrac{8}{11}+\dfrac{3}{11}+\dfrac{1}{2}=\dfrac{3}{7}+\dfrac{1}{2}+1=\dfrac{6+7+14}{14}=\dfrac{27}{14}\)

b: \(B=\dfrac{11}{17}+\dfrac{6}{17}-\dfrac{8}{19}-\dfrac{30}{19}+\dfrac{-3}{4}=1-2-\dfrac{3}{4}=-1-\dfrac{3}{4}=-\dfrac{7}{4}\)

c: \(C=1-\dfrac{1}{2}+\dfrac{1}{2}-\dfrac{1}{3}+\dfrac{1}{3}-\dfrac{1}{4}+...+\dfrac{1}{49}-\dfrac{1}{50}=\dfrac{49}{50}\)