1/15+4/27+3/15-1/27

=(1/15+3/15)+(4/27-1/27)

=4/15+3/27

=.......

= 1/15+3/15+4/27-1/27

=4/15+4/27-1/27

=56/135 - 1/27 = 17/45

chúc bạn học tốt !

1/15 + 4/27 + 3/15 - 1/27 = 1/15 + 3/15 + 4/27 -1/27

                                        = 4/15 + 3/27

                                         = 17/45

\(\dfrac{15^3}{-27}=\dfrac{\left(3.5\right)^3}{3^3}=\dfrac{3^3.5^3}{3^3}=\dfrac{5^3}{1}=125\)

\(\dfrac{15^3}{-27}=\dfrac{5^3\cdot3^3}{3^3}\cdot\left(-1\right)=-125\)

\(\frac{31}{135}\)

31/135

cả cách làm đâu bạn ????

a) \(...=\dfrac{5}{6}-\dfrac{4}{15}=\dfrac{75}{90}-\dfrac{24}{90}=\dfrac{51}{90}\)

b) \(...=\dfrac{1}{2}-\dfrac{1}{5}=\dfrac{5}{10}-\dfrac{2}{10}=\dfrac{3}{10}\)

\(\dfrac{25}{30}\) - \(\dfrac{4}{15}\) = \(\dfrac{5}{6}\) - \(\dfrac{4}{15}\) = \(\dfrac{17}{30}\)

\(\dfrac{27}{54}\) - \(\dfrac{3}{15}\) = \(\dfrac{1}{2}\) - \(\dfrac{1}{5}\) = \(\dfrac{3}{10}\) 

Bạn tự QĐMS nhé

Nguyễn Đức Trí kết bạn với tớ đi

ghi lại đoàn hoàn đc hăm :)?

a) 27.(15-12)-15.(27-12)

= 27.15-27.12-15.27-15.12

=405 - 324 - 405 - 180

= -504

\(\frac{12}{27}+\frac{5}{8}+\frac{2}{5}+\frac{15}{27}+\frac{3}{5}+\frac{3}{8}\)

\(=\left(\frac{12}{27}+\frac{15}{27}\right)+\left(\frac{5}{8}+\frac{3}{8}\right)+\left(\frac{2}{5}+\frac{3}{5}\right)\)

\(=1+1+1\)

\(=3\)

(12/27+15/27)+(5/8+3/8)+3/5

=1+1+3/5

=2+3/5

=13/5

chúc em học tốt

      \(\frac{12}{27}+\frac{5}{8}+\frac{2}{5}+\frac{15}{27}+\frac{3}{5}+\frac{3}{8}\)

\(=\left(\frac{12}{27}+\frac{15}{27}\right)+\left(\frac{5}{8}+\frac{3}{8}\right)+\left(\frac{2}{5}+\frac{3}{5}\right)\)

\(=1+1+1\)

\(=3\)

=-15+27-27+15-31=-31

a)510 

b)........

=[-15+(-25)+27]³

=(-40+27)³

=(-13)³

=-2197

- 2197