20.(17-111)-17.(222+20)

=20.(-94)-17.242

=(-1880)-4114

=-5994

tick nha bạn

15.(17-111)-17.(222+15)

=15.17+15.111-17.15-17.222

=15.17+15.11-17.15-17.2.111

=15.17+15.11-17.15-34.111

=[15.17-15.17]+[111.(15-34)]

=0+111.(-19)

=-2109

15 .(17-111)-17.(222+15)

= 15.17 - 15.111 - 17.222 -17.15 

= 17.15 - 17.15 - 15.111 - 17.2.111 

= 111( -15 - 17.2 ) 

= 111 . (-49) 

= 5439 

-2109

HI VỌNG LÀ VẬY

a) 17 + 15 + (-27)

= (17 - 27) + 15

= -10 + 15

= 5

b) 13.75 + 25.13 - 300

= 13.(75 + 26) - 300

= 13.100 - 300

= 1300 - 300

= 1000

c) 80 - (4.5² - 5.2³) + 2021⁰

= 80 - (4.25 - 5.8) + 1

= 80 - (100 - 40) + 1

= 80 - 60 + 1

= 20 + 1

= 21

\(\text{-567-(-113)+(-69)-(113-567)}\)

=\(-567+113-69-113+567\)

=\(\left(-567+567\right)\left(113-113\right)-69\)

=\(-69\)

\(\text{15.(17-111)-17.(22+15)}\)

\(=225-1665-3774-225\)

\(=\)\(\left(225-225\right)-\left(1665+3774\right)\)

\(=0-5439=-5439\)

\(2011+\left\{743-\left[2011-\left(275\right)\right]\right\}\)

\(=2011+\left\{743-\left[2011-275\right]\right\}\)

\(=2011+\left\{743-1754\right\}\)

\(=2011-1011\)

\(=1000\)

\(\frac{4}{17}x-\frac{2}{15}+\frac{2}{15}x-\frac{13}{17}\)

\(=\left(\frac{4}{17}x-\frac{2}{15}x\right)+\left(-\frac{2}{15}-\frac{13}{17}\right)\)

\(=\frac{26}{255}x-\frac{229}{255}\)

 = 249.17-249.111-17.3.111+17.51

 = 17.(249+51)-249.111-111.51

 = 17.300-111.(249+51)

 = 17.300-111.300

 = 300.(17-111)

 = 300.(-94)

 = -28200

Tk mk nha

-28200 nhé bn

​Tk mình đi nhé bn!

=-5439

tích mk nhé các bạn

bạn Myy   ơi tic mình nha!

bạn nhấn vào đúng 0 sẽ có đáp án

a)   \(199\left(15-17\right)-199\left(-17+5\right)\)

\(=199.15-199.17+199.17-199.5\)

\(=199.\left(15-5\right)\)

\(=199.10=1990\)

b)   \(73\left(8-59\right)-59\left(8-73\right)\)

\(=73.8-73.59-59.8+59.73\)

\(=8\left(73-59\right)\)

\(=8.14=112\)

Câu 9

a) 2/15 + (-3/5)

= 2/15 - 3/5

= 2/15 - 9/15

= -7/15

b) -5/7 + 3/7 . (-2/9)

= -5/7 - 2/21

= -15/21 - 2/21

= -17/21

c) 5/16 - (7/15 - 3/16) + 17/30

= 5/16 - 7/15 + 3/16 + 17/30

= (5/16 + 3/16) + (17/30 - 14/30)

= 1/2 + 1/10

= 5/10 + 1/10

= 6/10

= 3/5

\(a,\dfrac{2}{15}+\left(-\dfrac{3}{5}\right)\\ =\dfrac{2}{15}-\dfrac{3}{5}\\ =\dfrac{2}{15}-\dfrac{9}{15}\\ =-\dfrac{7}{15}\\ b,-\dfrac{5}{7}+\dfrac{3}{7}\times\left(-\dfrac{2}{9}\right)\\ =-\dfrac{5}{7}-\dfrac{2}{21}\\ =-\dfrac{15}{21}-\dfrac{2}{21}\\ =-\dfrac{17}{21}\\ c,\dfrac{5}{16}-\left(\dfrac{7}{15}-\dfrac{3}{16}\right)+\dfrac{17}{30}\\ =\dfrac{5}{16}-\dfrac{7}{15}+\dfrac{3}{16}+\dfrac{17}{30}\\ =\left(\dfrac{5}{16}+\dfrac{3}{16}\right)-\left(\dfrac{17}{15}+\dfrac{17}{30}\right)\\ =\dfrac{1}{2}-\dfrac{17}{10}\\ =\dfrac{5}{10}-\dfrac{17}{10}\\ =-\dfrac{6}{5}.\)