=(15/34+9/34-15/17)+(1/3+2/3)

=(24/34-15/17)+1

=-3/17+1

=14/17

ap dung nhan chia truoc cong tru sau

Sửa đề:

\(A=\dfrac{15}{34}+\dfrac{7}{21}+\dfrac{9}{34}-1\dfrac{15}{17}+\dfrac{2}{3}\)

\(=\dfrac{15}{34}+\dfrac{7}{21}+\dfrac{9}{34}-\dfrac{32}{17}+\dfrac{2}{3}\)

\(=-\dfrac{3}{17}\)

Cái hạng tử thứ 4 là gì vậy ạ?

\(A=\dfrac{15}{34}+\dfrac{1}{3}+\dfrac{9}{34}-\dfrac{32}{17}+\dfrac{2}{3}\)

\(A=\dfrac{15}{34}+\dfrac{1}{3}+\dfrac{9}{34}-\dfrac{64}{34}+\dfrac{2}{3}\)

\(A=\left(\dfrac{15}{34}+\dfrac{9}{34}-\dfrac{64}{34}\right)+\left(\dfrac{1}{3}+\dfrac{2}{3}\right)\)

\(A=\dfrac{40}{34}+1=2\dfrac{6}{34}\)

\(A=\dfrac{15}{34}+\dfrac{7}{21}+\dfrac{9}{34}-1\dfrac{15}{17}+\dfrac{2}{3}\)

\(=\dfrac{15}{34}+\dfrac{1}{3}+\dfrac{9}{34}-1\dfrac{15}{17}+\dfrac{2}{3}\)

\(=\left(\dfrac{15}{34}+\dfrac{9}{34}\right)+\left(\dfrac{1}{3}+\dfrac{2}{3}\right)-1\dfrac{15}{17}\)

\(=1+1-1\dfrac{15}{17}\)

\(=2-1\dfrac{15}{17}\)

\(=\dfrac{2}{17}\)

\(\dfrac{15}{34}+\dfrac{7}{21}+\dfrac{19}{34}-1\dfrac{15}{17}+\dfrac{2}{3}\)

= \(\left(\dfrac{15}{34}+\dfrac{19}{34}\right)+\left(\dfrac{7}{21}+\dfrac{2}{3}\right)-1\dfrac{15}{17}\)

= \(1+\left(\dfrac{7}{21}+\dfrac{14}{21}\right)-1\dfrac{15}{17}\)

= \(1+1-1\dfrac{15}{17}\)

= \(2-1\dfrac{15}{17}\)

= \(\dfrac{2}{17}\)

\(\dfrac{15}{34}-\dfrac{7}{21}+\dfrac{19}{34}-\dfrac{15}{17}-\dfrac{2}{3}\)

\(=\left(\dfrac{15}{34}+\dfrac{19}{34}\right)-\left(\dfrac{7}{21}+\dfrac{2}{3}\right)-\dfrac{15}{17}\)

\(=1-\left(\dfrac{7}{21}+\dfrac{14}{21}\right)-\dfrac{15}{17}\)

\(=1-1-\dfrac{15}{17}\)

\(=-\dfrac{15}{17}\)

\(\dfrac{15}{34}+\dfrac{7}{21}+\dfrac{19}{34}-\dfrac{32}{17}+\dfrac{2}{3}\) 

\(=\left(\dfrac{15}{34}+\dfrac{19}{34}\right)+\dfrac{7}{21}+\dfrac{-32}{17}+\dfrac{2}{3}\) 

\(=1+\dfrac{1}{3}+\dfrac{-32}{17}+\dfrac{2}{3}\) 

\(=1+\left(\dfrac{1}{3}+\dfrac{2}{3}\right)+\dfrac{-32}{17}\) 

\(=1+1+\dfrac{-32}{17}\) 

\(2+\dfrac{-32}{17}=\dfrac{2}{17}\)

a) (-15)+ 7. (-3)

=-15-21=-36

b) 21.(17-34)-22.(-15)

=21.(-17)+330=-357+330=-27

c) (-15).(-37)+(-6).9

=555-54=501

d) (-27).(-58)-(-14).8

=1566+112=1678

a) (-15)+ 7. (-3)

=(-15)+ (-21)=-36

b)21.(17-34)-22.(-15)

=21.(-17)-(-330)=(-357)-(-330)=-27

c) (-15).(-37)+(-6).9

=555+(-54)=501

d) (-27).(-58)-(-14).8

=1566-(-112)=1678

a) (-15) + 7.(-3)

= (-15) + (-21)

= -36.

b) 21.(17 - 34) - 22.(-15)

= 21.(-17) - (-330)

= 21.(-17) + 330

= (-357) + 330

= -27.

c) (-15).(-37) + (-6).9

= 555 + (-54)

= 501.

d) (-27).(-58) - (-14).8

= (-27).(-58) + 14.8

= 1566 + 112

= 1678.

\(A=\frac{15}{34}+\frac{7}{21}+\frac{9}{34}-1\frac{15}{17}+\frac{2}{3}\)

   \(=\frac{12}{17}+\frac{1}{3}-\frac{32}{17}+\frac{2}{3}\)

   \(=-\frac{20}{17}+\frac{1}{3}+\frac{2}{3}\)

   \(=-\frac{20}{17}+1\)

   \(=-\frac{3}{17}\)

\(B=16\frac{2}{7}:\left(-\frac{3}{5}\right)-28\frac{2}{7}:\left(-\frac{3}{5}\right)\)

   \(=\left(\frac{114}{7}-\frac{198}{7}\right):\left(-\frac{3}{5}\right)\)

   \(=\left(-12\right):\left(-\frac{3}{5}\right)\)

   \(=20\)

A\(=\frac{15}{34}+\frac{7}{21}+\frac{9}{34}-1\frac{15}{17}+\frac{2}{3}\)

\(=\left(\frac{15}{34}+\frac{9}{34}\right)+\left(\frac{7}{21}+\frac{2}{3}\right)-1\frac{15}{17}\)

\(=\left(\frac{14}{17}-\frac{15}{17}\right)+1-1\)

\(=-\frac{1}{17}\)

\(B=16\frac{2}{7}:\left(-\frac{3}{5}\right)-28\frac{2}{7}:\left(-\frac{3}{5}\right)\)

\(B=-\frac{3}{5}.\left(16\frac{2}{7}-28\frac{2}{7}\right)\)

\(B=-\frac{3}{5}.\left(-12\right)\)

\(B=\frac{36}{5}\)

Hoctot

A=\(\frac{15}{34}\)+ \(\frac{7}{21}\)+  \(\frac{9}{34}\)- 1\(\frac{15}{17}\)+ \(\frac{2}{3}\)

   = ( \(\frac{15}{34}\)+ \(\frac{9}{34}\)) + ( \(\frac{7}{21}\)+ \(\frac{2}{3}\)) - \(\frac{32}{17}\)

  =  \(\frac{24}{34}\)+ ( \(\frac{7}{21}\)+ \(\frac{14}{21}\)) - \(\frac{32}{17}\)

  =\(\frac{12}{17}\)+ \(\frac{21}{21}\)- \(\frac{32}{17}\)

  = ( \(\frac{12}{17}\) - \(\frac{32}{17}\)) +1

  =\(\frac{-20}{17}\)+ \(\frac{17}{17}\)

  = \(\frac{-3}{17}\)