bài 1 thực hiện phép tính, tính nhanh nếu có thể
a, \(\frac{-11}{23}.\frac{6}{7}+\frac{8}{7}.\frac{-11}{23}-\frac{1}{23}\)
b,\(0,75.1\frac{7}{9}-1\frac{2}{5}:\frac{-21}{20}\)
c,\(2.\frac{3}{7}+\left(\frac{2}{9}-1\frac{3}{7}\right)-\frac{5}{3}:\frac{1}{9}\)
d,\(11\frac{1}{4}-\left(2\frac{5}{7}+5\frac{1}{4}\right)\)
e,\(\left(6-2\frac{4}{5}\right).3\frac{1}{8}-1\frac{3}{5}:25\%\)
g,\(0,2.\frac{15}{36}-\left(\frac{2}{5}+\frac{2}{3}\right):1\frac{1}{5}\)
h,\(2\frac{1}{3}-\frac{1}{3}.\left(\frac{-3}{2}+\left(\frac{2}{3}+0,4.5\right)\right)\)
i,\(\frac{1}{3}.\frac{5}{7}-\frac{7}{27}.\frac{36}{14}\)
k,\(\left(\frac{-5}{28}+1,75+\frac{8}{35}\right):\left(-3\frac{9}{20}\right)\)
l,\(\left(20+9\frac{1}{4}\right):2\frac{1}{4}\)
m,\(\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+...+\frac{1}{12.13}\)
n,\(\frac{5}{1.3}+\frac{5}{3.5}+\frac{5}{5.7}+...+\frac{5}{99.101}\)
\(12^n:2^{2n}=3^n.\left(2^2\right)^n:2^{2n}=3^n.2^{2n}:2^{2n}=3^n\)
\(3^8:3^4+2^2.2^3=3^4+2^5=81+32=113\)
\(\left(7^{1997}-7^{1995}\right)\left(7^{1994}\cdot7\right)=7^{1995}\left(7^2-1\right)\cdot7^{1995}=7^{1995\cdot2}\cdot48=7^{3990}\cdot48\)
\(4^{14}\cdot5^{28}=4^{14}\cdot\left(5^2\right)^{14}=\left(4\cdot25\right)^{14}=100^{14}\)
\(3\cdot4^2-2\cdot3^2=3\cdot2^4-2\cdot3^2=6\left(2^3-3\right)=6\cdot5=30\)
\(18^3:9^3=\left(18:9\right)^3=2^3=8\)
\(\left(2^8+8^3\right):\left(2^5\cdot2^3\right)=\left(2^8+2^9\right):2^8=\dfrac{2^8}{2^8}+\dfrac{2^9}{2^8}=1+2=3\)
\(16\cdot64\cdot8^2:\left(4^3.2^5.16\right)=2^4\cdot2^6\cdot2^6:\left(2^6\cdot2^5\cdot2^4\right)=2\)
\(5\cdot2^9\cdot6^{10}-7\cdot2^{29}\cdot27^6=5\cdot2^9\cdot2^{10}\cdot3^{10}-7\cdot2^{29}\cdot3^{18}=2^{19}\cdot3^{10}\left(5\cdot3^{10}-7\cdot2^{10}\cdot8\right)\)