(37-17).(-5)+23.(-13-17)

=[(37-17).(-5)]+23.[(-13)-17]

=[20.(-5)]+23.[(-13)+(-17)]

=(-100)+23.(-30)

=(-100)+[23.(-30)]

=(-100)+(-690)

=-790

Nếu đúng cho mình một tick nhé!

a)48.45+55.48=(45+55).48=100.48=4800

b)57.37+57.23+57.40=57.(23+37+40)=57.100=5700

c)25.5.4.17.2=(25.4).(5.17.2)=100.170=17000

d)127.45+55.127-27.100=127.(45+55)-(27.100)=127.100-27.100=(127-27).100=100.100=10000

e)543+165+457+35=(543+457)+(165+35)=1000+200=1200

g)13.58.4+32.6.2+52.10=(52.58)+(52.32)+52.10=52.(58+32+10)=52.100=5200

h)25.5.4.17.2=(25.4).(17.2.5)=100.170=17000

k)(3737.43-4343.37):(2+4+6+...+100)=(37.101.43-43.101.37):(2+4+6+...+100)=0.(2+4+6+...+100)=0

i)1+5+9+...+29+33+37=(1+37)+(5+33)+...=190

a=4800

b=5700

c=17000

d=10000

e=1200

...

phần còn lại bạn tự làm nhé

mình nhớ là bạn đã đăng r.Ko có việc j làm thì cx đừng đăng lại chứ!!!!!!!!!1

Câu hỏi của Nguyễn Bích Hoa - Toán lớp 6 | Học trực tuyến

Bài 1:

a; \(\dfrac{5}{18}\) + \(\dfrac{8}{19}\) - \(\dfrac{7}{21}\) + (- \(\dfrac{10}{36}\) + \(\dfrac{11}{19}\)  + \(\dfrac{1}{3}\)) - \(\dfrac{5}{8}\)

=  \(\dfrac{5}{18}\) + \(\dfrac{8}{19}\) - \(\dfrac{1}{3}\) -\(\dfrac{10}{36}\) + \(\dfrac{11}{19}\) + \(\dfrac{1}{3}\) - \(\dfrac{5}{8}\)

= (\(\dfrac{5}{18}\) - \(\dfrac{10}{36}\)) + (\(\dfrac{8}{19}\) + \(\dfrac{11}{19}\)) - (\(\dfrac{1}{3}\) - \(\dfrac{1}{3}\)) - \(\dfrac{5}{8}\)

= (\(\dfrac{5}{18}\) - \(\dfrac{5}{18}\)) + \(\dfrac{19}{19}\) - 0 - \(\dfrac{5}{8}\)

= 0 + 1 - \(\dfrac{5}{8}\)

= \(\dfrac{3}{8}\)

b; \(\dfrac{1}{13}\) + (\(\dfrac{-5}{18}\) - \(\dfrac{1}{13}\) + \(\dfrac{12}{17}\)) - (\(\dfrac{12}{17}\) - \(\dfrac{5}{18}\) + \(\dfrac{7}{5}\))

= \(\dfrac{1}{13}\) - \(\dfrac{5}{18}\) - \(\dfrac{1}{13}\) + \(\dfrac{12}{17}\) - \(\dfrac{12}{17}\) + \(\dfrac{5}{18}\) - \(\dfrac{7}{5}\)

= (\(\dfrac{1}{13}\) - \(\dfrac{1}{13}\)) + (\(\dfrac{12}{17}\) - \(\dfrac{12}{17}\)) + (-\(\dfrac{5}{18}\) + \(\dfrac{5}{18}\)) - \(\dfrac{7}{5}\)

= 0 + 0 + 0 - \(\dfrac{7}{5}\)

= - \(\dfrac{7}{5}\)

Bài 1 c;

   \(\dfrac{15}{14}\) - (\(\dfrac{17}{23}\) - \(\dfrac{80}{87}\) + \(\dfrac{5}{4}\)) + (\(\dfrac{17}{23}\) - \(\dfrac{15}{14}\) + \(\dfrac{1}{4}\))

=  \(\dfrac{15}{14}\) - \(\dfrac{17}{23}\) + \(\dfrac{80}{87}\) - \(\dfrac{5}{4}\) + \(\dfrac{17}{23}\) - \(\dfrac{15}{14}\) + \(\dfrac{1}{4}\)

= (\(\dfrac{15}{14}-\dfrac{15}{14}\)) + (\(-\dfrac{17}{23}+\dfrac{17}{23}\)) - (\(\dfrac{5}{4}\) - \(\dfrac{1}{4}\)) + \(\dfrac{80}{87}\)

= 0 + 0 - 1 + \(\dfrac{80}{87}\)

= - \(\dfrac{7}{87}\)

k) (-23)+105=82

g)(-5)+(-248)=-253

a) Ta có: 2763+152

=2915

b) Ta có: (-7)+(-14)

=-(7+14)

=-21

e) Ta có: (-35)+(-9)

=-(35+9)

=-44

g) Ta có: (-5)+(-248)

=-(5+248)

=-253

k) Ta có: (-23)+105

=105-23

=82

B10:

a)23.27=621

b)-23.27=-621

c)23.(-23)=529

d)(-23).(-27)=621

Thêm dấu - trc kq câu c :vv

mk chỉ giúp câu a thôi nhé:

a)2020.2019+2020.(-2019)

=2020.[2019+(-2019)]

=2020.0

=0

Câu a:

x + 25 + (-17) + 63

= x + [(25 - 17) + 63]

= x + [8 + 63]

= x + 71

Câu b:

-75 - (p+ 20) + 95

= -75 - p - 20 + 95

= (-75 - 20 + 95) - p

= (-95 + 95) - p

= 0 - p

= -p