5/6 + 9/12 : 18/5 = 5/6 + 3/4 : 18/5

                          = 5/6 + 3/4 x 5/18

                         = 5/6 + 15/72

                         = 5/6 + 5/24

                         = 20/24 + 5/24

                         = 25/24

5/7 + 9/8 - 15/28 = 40/56 + 63/56 - 30/56

                          = 103/56 - 30/56

                          = 73/56

\(\dfrac{5}{6}+\dfrac{9}{12}:\dfrac{18}{5}\)
\(=\dfrac{5}{6}+\dfrac{5}{24}\)
\(=\dfrac{25}{24}\)
\(---\)
\(\dfrac{5}{7}+\dfrac{9}{8}-\dfrac{15}{28}\)
\(=\dfrac{103}{56}-\dfrac{15}{28}\)
\(=\dfrac{73}{56}\)

5/6 + 9/12 : 18/5

=5/6 + 5/24

=25/24

nhầm nha,= 0 nha ban

đáp án là 0

\(\dfrac{15}{8}:\dfrac{45}{6}-\dfrac{1}{13}\left(\dfrac{4}{9}-\dfrac{1}{12}\right)\)

\(=\dfrac{15}{8}\cdot\dfrac{6}{45}-\dfrac{1}{13}\left(\dfrac{48-9}{108}\right)\)

\(=\dfrac{1}{4}-\dfrac{1}{13}\cdot\dfrac{13}{36}\)

\(=\dfrac{1}{4}-\dfrac{1}{36}=\dfrac{2}{9}\)

2/9

\(\frac{2^{19}.27^3+15^4.4^9.9^4}{6^9.2^{10}+12^{10}}\)

\(=\frac{2^{19}.\left(3^3\right)^3+\left(3.5\right)^4.\left(2^2\right)^9.\left(3^2\right)^4}{\left(2.3\right)^9.2^{10}+\left(2^2.3\right)^{10}}\)

\(=\frac{2^{19}.3^9+3^{12}.5^4.2^{18}}{2^{19}.3^9+2^{20}.3^{10}}\)

\(=\frac{2^{18}.3^9.\left(2+3^3+5^4\right)}{2^{19}.3^9.\left(1+2+3\right)}\)

\(=\frac{654}{2.6}\)

\(=\frac{109}{2}\)

Chúc bn học tốt !!!!

giúp mk ik, năn nỉ đó.

\(=\dfrac{2^{19}\cdot3^9-3\cdot3^8\cdot2^{18}\cdot5}{2^{19}\cdot3^9+2^{20}\cdot3^{10}}=\dfrac{-3^{10}\cdot2^{18}}{2^{19}\cdot3^9\cdot7}=-\dfrac{3}{14}\)

C = 5 . 4 3 + 2 4 . 5 + 41 = 441 = 21 2

C = 5 . 4 3 + 2 4 . 5 = 400 = 20 2

\(\dfrac{2^{15}.9^4}{6^6.8^3}=\dfrac{2^{15}.3^8}{2^6.3^6.2^9}=\dfrac{2^{15}.3^8}{2^{15}.3^6}=3^2=9\)

Thanks nha