Ghi đầy đủ nha

bn có thể ghi rõ ràng đc ko?

a)\(-\dfrac{3}{7}+\dfrac{5}{13}+\dfrac{3}{7}\) 

=\(\left(-\dfrac{3}{7}+\dfrac{3}{7}\right)+\dfrac{5}{13}\) 

=\(0+\dfrac{5}{13}\) 

=\(\dfrac{5}{13}\)

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 + \(\dfrac{80}{87}\)

= - \(\dfrac{7}{87}\)

Bài 1 d; 

   \(\dfrac{1}{25}\) - \(\dfrac{4}{27}\) + (-\(\dfrac{23}{27}\) + \(\dfrac{-1}{25}\) - \(\dfrac{5}{43}\)) + \(\dfrac{5}{43}\) - \(\dfrac{4}{7}\)

= \(\dfrac{1}{25}\) - \(\dfrac{4}{27}\) - \(\dfrac{23}{27}\) - \(\dfrac{1}{25}\) - \(\dfrac{5}{43}\) + \(\dfrac{5}{43}\) - \(\dfrac{4}{7}\)

= (\(\dfrac{1}{25}\) - \(\dfrac{1}{25}\)) - (\(\dfrac{4}{27}\) + \(\dfrac{23}{27}\)) - (\(\dfrac{5}{43}\) - \(\dfrac{5}{43}\)) - \(\dfrac{4}{7}\)

= 0 - 1 - 0 - \(\dfrac{4}{7}\)

= \(\dfrac{-11}{7}\)

Ai rảnh mà làm hộ mày, ngu như con chó mới không biết làm

khó hiểu quá

mày bảo tao ngu mày cũng ngu thế thôi câm mồm đi

đéo làm đc cứ thích sĩ

a. ( 23 - 21) + ( 19 - 17) + ( 15 - 13) + ( 11 - 9) + ( 7 - 5) + ( 3 - 1) 

= 2 + 2 + 2 + 2 + 2 + 2 

= 2 x 6

= 12

b. ( 24 - 22 ) + ( 20 - 18 ) + ( 16 - 14 ) + ( 12 - 10) + ( 8 - 6 ) + ( 4 - 2) 

= 2 + 2 + 2 + 2 + 2 + 2 

= 2 x 6 

= 12

2:

a: \(2^2\cdot3-4=4\cdot3-4=12-4=8\)

b: \(16-2^3\cdot2=16-2^4=16-16=0\)

c: \(4^2-4\cdot2=16-8=8\)

d: \(3^3-2\cdot3^2=27-2\cdot9=27-18=9\)

e: \(7^2-9\cdot2^2=49-9\cdot4=49-36=13\)

f: \(2^2\cdot3+4^2=4\cdot3+16=12+16=28\)

Bài 1:

a: \(13+21\cdot5-\left(198:11-8\right)\)

\(=13+105-18+8\)

=21+87

=108

b: \(272:16-5+4\cdot\left(30-5-255:17\right)\)

\(=17-5+4\cdot\left(30-5-15\right)\)

\(=12+4\cdot10=12+40=52\)

c: \(15\cdot24-14\cdot5\cdot\left(145:5-27\right)\)

\(=360-70\left(29-27\right)\)

=360-140

=220

d: \(18\cdot3-18\cdot2+3\cdot\left(\dfrac{51}{17}\right)\)

\(=18\left(3-2\right)+3\cdot3\)

=18+9

=27

e: \(64+115+36-25\cdot8\cdot6\cdot2^2\cdot3+4^2\)

\(=100+115-200\cdot6\cdot4\cdot3+16\)

\(=231-14400=-14169\)

f: \(15\cdot8-\left(17-30+83\right)-144:6\)

\(=120-24-\left(100-30\right)\)

=96-70

=26

24/10<25/10

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; \(\dfrac{-5}{21}\) - \(\dfrac{25}{21}\) - \(\dfrac{-1}{21}\)

  = \(\dfrac{-5}{21}\) - \(\dfrac{25}{21}\) + \(\dfrac{1}{21}\)

 =  \(\dfrac{-5-25+1}{21}\)

= \(\dfrac{-29}{21}\)

a)12/5<5/2

b)6/15>3/8

c)\(\frac{17}{18}<\frac{18}{19}\)

d) \(\frac{24}{23}\) < \(\frac{23}{22}\)

\(A=\frac{2}{7}+\frac{-3}{8}+\frac{11}{7}+\frac{1}{3}+\frac{1}{7}+\frac{5}{-8}\)

\(A=\left(\frac{2}{7}+\frac{11}{7}+\frac{1}{7}\right)+\left(\frac{-3}{8}+\frac{5}{-8}\right)+\frac{1}{3}\)

\(A=2-1+\frac{1}{3}\)

\(A=\frac{4}{3}\)

\(B=\frac{3}{17}+\frac{-5}{13}+\frac{-18}{35}+\frac{14}{17}+17\)

\(B=\left(\frac{3}{17}+\frac{14}{17}\right)+\frac{-5}{13}+\frac{-18}{35}+17\)

\(B=1+\frac{-5}{13}+\frac{-18}{35}+17\)

\(B=18+\frac{-5}{13}+\frac{-18}{35}\)

\(B=\frac{7781}{455}\)