A = \(\dfrac{-5}{12}\)x\(\dfrac{2}{11}\)+\(\dfrac{-5}{12}\)x\(\dfrac{9}{11}\)+\(\dfrac{5}{12}\)

A= \(\dfrac{-5}{12}\)(\(\dfrac{2}{11}\)+\(\dfrac{9}{11}\)-1)

A = 0

a) (137x25-25x37):10

=25x(137-37):10

=25x100:10

=2500:10

=250

b) 2/7x21/4-2/7:13/4

=2/7x21/4-2/7x4/13

=2/7x(21/4-4/13)

=2/7x257/52

=257/182

c)(124x237+152):(870+235x122)

=(29388+152):(870+28670)

=29540:29540

=1

a) (137 x 25 - 25 x 37 ) : 10 = (25 x (137 - 37) ) : 10

                                       = (25 x 100) : 10

                                       = 2500 : 10

                                       = 250

a)=(3425-925):10

=25200:10

=250

b)=3/2-8/91

=257/182

c)=(29388+152):(870+28670)

=29540:29540

=1

d)=1161+1539/72

=2700/72=75/2

e)=10/77+45/77x9/7

=10/77+405/539

=475/539

li ke cho mình nha Lam Le thi

\(\dfrac{-5}{7}.\dfrac{2}{11}-\dfrac{5}{11}.\dfrac{9}{7}-2\dfrac{5}{7}\)

\(=\dfrac{-2}{7}.\dfrac{5}{11}-\dfrac{5}{11}.\dfrac{9}{7}-\dfrac{19}{7}\)

\(=\dfrac{5}{11}.\left(\dfrac{-2}{7}-\dfrac{9}{7}\right)-\dfrac{19}{7}\)

\(=\dfrac{5}{11}.\dfrac{-11}{7}-\dfrac{19}{7}\)

\(=\dfrac{-5}{7}-\dfrac{19}{7}\)

\(=\dfrac{-24}{7}\)

\(\dfrac{-5}{7}.\dfrac{2}{11}-\dfrac{5}{11}.\dfrac{9}{7}-2\dfrac{5}{7}\)

\(=\dfrac{-2}{7}.\dfrac{5}{11}-\dfrac{5}{11}.\dfrac{9}{7}-\dfrac{19}{7}\)

\(=\dfrac{5}{7}\left(\dfrac{-2}{7}-\dfrac{9}{7}\right)-\dfrac{19}{7}\)

\(=\dfrac{5}{7}.\dfrac{-11}{7}-\dfrac{19}{7}\)

\(=\dfrac{5.\left(-11\right)}{11.7}-\dfrac{19}{7}\)

\(=\dfrac{-5.11}{11.7}-\dfrac{19}{7}\)

\(=\dfrac{-5}{7}-\dfrac{19}{7}\)

\(=\dfrac{-5-19}{7}\)

\(=\dfrac{\left(-5\right)+\left(-19\right)}{7}\)

\(=\dfrac{-24}{7}\)

a: \(\frac{3^{10}\cdot\left(-5\right)^{21}}{\left(-5\right)^{20}\cdot3^{12}}=\frac{-3^{10}\cdot5^{21}}{3^{12}\cdot5^{20}}=\frac{-5}{3^2}=-\frac59\)

b: \(\frac{-11^5\cdot13^7}{11^5\cdot13^8}=\frac{-11^5}{11^5}\cdot\frac{13^7}{13^8}=-\frac{1}{13}\)

c: \(2^{10}\cdot3^{10}-2^{10}\cdot3^9\)

\(=2^{10}\cdot3^9\cdot\left(3-1\right)\)

\(=2^{11}\cdot3^9\)

Ta có: \(\frac{2^{10}\cdot3^{10}-2^{10}\cdot3^9}{2^9\cdot3^{10}}\)

\(=\frac{2^{11}\cdot3^9}{2^{10}\cdot3^9}=2\)

d: \(5^{11}\cdot7^{12}+5^{11}\cdot7^{11}\)

\(=5^{11}\cdot7^{11}\left(7+1\right)=5^{11}\cdot7^{11}\cdot8\)

\(5^{12}\cdot7^{12}+9\cdot5^{11}\cdot7^{11}\)

\(=5^{11}\cdot7^{11}\left(5\cdot7+9\right)\)

\(=5^{11}\cdot7^{11}\left(35+9\right)=5^{11}\cdot7^{11}\cdot44\)

Ta có: \(\frac{5^{11}\cdot7^{12}+5^{11}\cdot7^{11}}{5^{12}\cdot7^{12}+9\cdot5^{11}\cdot7^{11}}\)

\(=\frac{5^{11}\cdot7^{11}\cdot8}{5^{11}\cdot7^{11}\cdot44}=\frac{8}{44}=\frac{2}{11}\)

\(\frac{5^{11}.7^{12}+5^{11}.7^{11}}{5^{12}.7^{12}+9.5^{11}.7^{11}}\)

=\(\frac{5^{11}.7^{11}\left(7+1\right)}{5^{11}.7^{11}\left(5.7+9\right)}\)

= \(\frac{8}{35+9}\)

= \(\frac{8}{44}\)

= \(\frac{2}{11}\)

5 12 .7 12 +9.5 11 .7 11 5 11 .7 12 +5 11 .7 11 = 5 11 . 7 11 ( 7 + 1 ) 5 11 . 7 11 ( 5.7 + 9 ) 5 11 .7 11 (5.7+9) 5 11 .7 11 (7+1) = 8 35 + 9 35+9 8 = 8 44 44 8 = 2 11 11 2

11 * 9 +11 * 1 + 11 * 89 +11

=99 + 11 + 979 + 11

= 110 + 990

=1100

= 11x(9+1+89+1)

= 11x100

=1100

ticks nha bạn