\(A=\left(27,54.\frac{11}{16}-3.405\right):3\)

\(A=\left(\frac{15147}{800}-3.405\right):3\)

\(A=\frac{12423}{800}:3\)

\(A=\frac{4141}{800}\)

\(B=\left(\frac{1}{6}+0,1+\frac{1}{5}\right):\left(\frac{1}{6}+0,1-\frac{1}{5}\right)\)

\(B=\frac{7}{15}:\frac{1}{15}\)

\(B=7\)

\(C=\left(0,5-\frac{1}{3}+0,25\right):\left(0,25-\frac{1}{6}\right)\)

\(C=\frac{5}{12}:\frac{1}{12}\)

\(C=5\)

\(D=\frac{13,5.1420+4,5.780.3}{3+6+9+...+24+27}\)

              Số số hạng từ 3 đến 27 là:
                      (27-3):3+1=9(số hạng)

              Tổng dãy số từ 3 đến 27 là:

                       (27+3)x9:2=135

\(D=\frac{13,5.1420+13,5.780}{135}\)

\(D=\frac{13,5.\left(1420+780\right)}{135}\)

\(D=2200\)

Dấu . là dấu nhân

a) \(\left(-5\right)^{-1}=-\dfrac{1}{5}\)

b) \(2^0\cdot\left(\dfrac{1}{2}\right)^{-5}=1\cdot32=32\)

c) \(6^{-2}\cdot\left(\dfrac{1}{3}\right)^{-3}:2^{-2}\)

\(=\dfrac{1}{36}\cdot27:\dfrac{1}{4}\)

\(=\dfrac{27\cdot4}{36}=3\)

\(P=\left(-0,5-\frac{3}{5}\right):\left(-3\right)+\frac{1}{3}-\left(-\frac{1}{6}\right):\left(-2\right)\)

\(P=\left(-1,1\right):\left(-3\right)+\frac{1}{3}+\frac{1}{6}:\left(-2\right)\)

\(P=\frac{11}{30}+\frac{1}{3}+\left(-\frac{1}{12}\right)\)

\(P=\frac{37}{60}\)

\(Q=\left(\frac{2}{25}-1,008\right):\frac{4}{7}:\left[\left(3\frac{1}{4}-6\frac{5}{9}\right).2\frac{2}{17}\right]\)

\(Q=\left(-0,928\right):\frac{4}{7}:\left[\left(-\frac{119}{36}\right).2\frac{2}{17}\right]\)

\(Q=\left(-1,624\right):\left(-\frac{245}{36}\right)\)

\(Q=\frac{1044}{4375}\)

a) \(0,2 + 2,5:\frac{7}{2} = \frac{2}{{10}} + \frac{25}{10}:\frac{7}{2} = \frac{1}{5} + \frac{25}{10}.\frac{2}{7} \\= \frac{1}{5} + \frac{5}{7} = \frac{7}{{35}} + \frac{{25}}{{35}} = \frac{{32}}{{35}}\)

b)

\(\begin{array}{l}9.{\left( {\frac{{ - 1}}{3}} \right)^2} - {\left( { - 0,1} \right)^3}:\frac{2}{{15}}\\ = 9.\frac{1}{9} - {\left( {\frac{{ - 1}}{{10}}} \right)^3}:\frac{2}{{15}}\\ = 1 - \frac{{ - 1}}{{1000}}:\frac{2}{{15}}\\ = 1 - \frac{{ - 1}}{{1000}}.\frac{{15}}{2}\\ = 1 + \frac{3}{{400}}\\=\frac{400}{400}+\frac{3}{400}\\ = \frac{{403}}{{400}}\end{array}\)

d: \(D=-8\cdot\left(\dfrac{3}{4}-\dfrac{1}{4}\right):\left(\dfrac{9}{4}-\dfrac{7}{6}\right)\)

\(=-8\cdot\dfrac{1}{2}:\dfrac{27-14}{12}\)

\(=-4:\dfrac{13}{12}\)

\(=-4\cdot\dfrac{12}{13}=-\dfrac{48}{13}\)

e: \(E=5\cdot4-4\cdot3+5-0.3\cdot20\)

=20-12+5-6

=8+5-6

=13-6=7

f: \(F=\dfrac{9}{4}+\dfrac{5}{6}-\dfrac{3}{2}:6\)

\(=\dfrac{9}{4}+\dfrac{5}{6}-\dfrac{3}{12}\)

\(=\dfrac{27}{12}+\dfrac{10}{12}-\dfrac{3}{12}=\dfrac{34}{12}=\dfrac{17}{6}\)

\(P=\left(\dfrac{-1}{2}-\dfrac{3}{5}\right):\left(-3\right)+\dfrac{1}{3}-\dfrac{1}{6}:2\)

\(=\left(\dfrac{1}{2}+\dfrac{3}{5}\right):3+\dfrac{1}{3}-\dfrac{1}{12}\)

\(=\dfrac{11}{10}\cdot\dfrac{1}{3}+\dfrac{1}{4}\)

\(=\dfrac{11}{30}+\dfrac{1}{4}=\dfrac{22}{60}+\dfrac{15}{60}=\dfrac{37}{60}\)

\(Q=\left(\dfrac{2}{25}-\dfrac{126}{125}\right)\cdot\dfrac{7}{4}:\left[\dfrac{-119}{36}\cdot\dfrac{36}{17}\right]\)

\(=\dfrac{-116}{125}\cdot\dfrac{7}{4}:\left(-7\right)\)

\(=\dfrac{116}{125}\cdot\dfrac{7}{4}\cdot\dfrac{1}{7}=\dfrac{29}{125}\)