\(\left(9\frac{4}{7}+3\frac{7}{13}\right)-4\frac{4}{7}\)

\(=9\frac{4}{7}+3\frac{7}{13}-4\frac{4}{7}\)

\(=\left(9\frac{4}{7}-4\frac{4}{7}\right)+3\frac{7}{13}\)

\(=5+3\frac{7}{13}\)

\(=4\frac{13}{13}+3\frac{7}{13}\)

\(=7\frac{20}{13}\)( ở đây nếu cần đổi ra phân số thì ra bằng \(\frac{111}{13}\))

B=hon so 8 7/13

chuc ban hoc tot

\(\left(\frac{1999}{2011}-\frac{2011}{1999}\right)-\left(\frac{-12}{1999}-\frac{12}{2011}\right)\)

\(=\frac{1999}{2011}-\frac{2011}{1999}-\frac{12}{1999}+\frac{12}{2011}\)

\(=(\frac{1999}{2011}+\frac{12}{2011})-(\frac{2011}{1999}-\frac{12}{1999})\)

\(=1-1=0\)

\(\left(\frac{1999}{2011}-\frac{2011}{1999}\right)-\left(\frac{-12}{1999}-\frac{12}{2011}\right)\)

\(=\frac{1999}{2011}-\frac{2011}{1999}+\frac{12}{1999}+\frac{12}{2011}\)

\(=\left(\frac{1999}{2011}+\frac{12}{2011}\right)+\left(\frac{-2011}{1999}+\frac{12}{1999}\right)\)

\(=1-1\)

\(=0\)

Linz

=>x.(3/4-4/5)=7/10

=>x.(-1/20)=7/10

=>     x      =7/10:(-1/20)

 =>     x     =-14

 3/4x-4/5      x     =    7/10

(3/4-4/5)       x    =    7/10

15/20-16/20 x    =     7/10

-1/20            x    =     7/10 

                    x    =     7/10: (-1)/20

                   x     =   7/10 . -20

                   x     =   -14

k cho mk nha !!!!!!!!! mk ko nhanh nhưng cũng đúng ha

\(0,5.\frac{4}{3}.25\%:\frac{2}{5}+\frac{3}{5}\)

\(=\frac{1}{2}.\frac{4}{3}.\frac{1}{4}.\frac{5}{2}+\frac{3}{5}\)

\(=\frac{5}{12}+\frac{3}{5}\)

\(=\frac{25}{60}+\frac{36}{60}\)

\(=\frac{71}{60}\)

    0,5.4/3.25%:2/5+3/5

=  1/2.4/3.1/4:2/5+3/5

=  2/3.1/4.5/2+3/5

=  1/6.5/2+3/5

=   5/12+3/5

=   25/60+36/60

=   61/60

7/2-2x=22/3:4/3

7/2-2x=11/2

2x=7/2-11/2

2x=-2

x=-2:2

x=-1

( 7/2 - 2x) . 4/3 =  22/3

7/2 - 2x             = 22/3:4/3

7/2 - 2x              =22/3.3/4

7/2 - 2x              =11/2

        2x              =7/2-11/2

       2x                =-2

        x                = -2 : 2

       x                 =  -1