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1 tháng 8 2019

\(a,a^3\cdot a^9=a^{12}\)

\(b,\left(a^5\right)^7=a^{35}\)

\(c,\left(a^6\right)^4\cdot a^{12}=a^{24}\cdot a^{12}=a^{36}\)

\(d,4\cdot5^2-2\cdot3^2=2^2\cdot5-2\cdot3^2=2\cdot\left(2\cdot5+3^2\right)=2\cdot19=38\)

\(e,5^6:5^3+3^3\cdot3^2=5^3+3^5\)

1 tháng 8 2019

a,a3.a9=a3+9=a12

b,(a5)7=a5.7=a35

Mấy câu tiếp theo bn lám tương tự!

29 tháng 4 2019

a) \(=\frac{6}{7}+\frac{5}{8}:5-\frac{3}{16}.4\)

     \(=\frac{6}{7}+\frac{1}{8}-\frac{3}{4}\)

   \(=\frac{13}{56}\)

29 tháng 4 2019

b) \(=\frac{3}{2}+\frac{1}{2}.\frac{7}{18}:\frac{7}{12}\)

     \(=\frac{3}{2}+\frac{1}{3}\)

      \(=\frac{11}{6}\)

17 tháng 4 2017

\(A=11\dfrac{3}{13}-\left(2\dfrac{4}{7}+5\dfrac{3}{13}\right)\)

\(A=11\dfrac{3}{13}-5\dfrac{3}{13}-2\dfrac{4}{7}\)

\(A=6-2\dfrac{4}{7}\)

\(A=5\dfrac{7}{7}-2\dfrac{4}{7}\)

\(A=3\dfrac{3}{7}\)

\(B=\left(6\dfrac{4}{9}+3\dfrac{7}{11}\right)-4\dfrac{4}{9}\)

\(B=\left(6\dfrac{4}{9}-4\dfrac{4}{9}\right)+3\dfrac{7}{11}\)

\(B=2+3\dfrac{7}{11}\)

\(B=5\dfrac{7}{11}\)

\(C=\dfrac{-5}{7}.\dfrac{2}{11}+\dfrac{-5}{7}-\dfrac{9}{11}+1\dfrac{5}{7}\)

\(C=\dfrac{-5}{7}.\left(\dfrac{2}{11}+1\right)-\dfrac{9}{11}+1\dfrac{5}{7}\)

\(C=\dfrac{-5}{7}.\dfrac{13}{11}-\dfrac{9}{11}+1\dfrac{5}{7}\)

\(C=\dfrac{-65}{77}-\dfrac{9}{11}+1\dfrac{5}{7}\)

\(C=\dfrac{4}{11}+1\dfrac{5}{7}\)

\(C=\dfrac{160}{11}\)

\(D=0,7.2\dfrac{2}{3}.20.0,375.\dfrac{5}{28}\)

\(D=\dfrac{7}{10}.\dfrac{8}{3}.20.\dfrac{375}{1000}.\dfrac{5}{28}\)

\(D=\dfrac{7}{28}=\dfrac{5}{2}\)

\(E=\left(-6,17+3\dfrac{5}{9}-2\dfrac{36}{97}\right)\left(\dfrac{1}{3}-0,25-\dfrac{1}{12}\right)\)

\(E=\left(-6,17+3\dfrac{5}{9}-2\dfrac{36}{97}\right)\left(\dfrac{1}{3}-\dfrac{1}{4}-\dfrac{1}{12}\right)\)

\(E=\left(-6,17+3\dfrac{5}{9}-2\dfrac{36}{97}\right)\left(\dfrac{1}{12}-\dfrac{1}{12}\right)\)

\(E=\left(-6,17+3\dfrac{5}{9}-2\dfrac{36}{97}\right).0\)

\(\Rightarrow E=0\)

a: \(=\dfrac{5\cdot\left(8-6\right)}{10}=\dfrac{5\cdot2}{10}=1\)

b: \(\dfrac{\left(-4\right)^2}{5}=\dfrac{16}{5}\)

\(B=\dfrac{3}{7}-\dfrac{1}{5}-\dfrac{3}{7}=-\dfrac{1}{5}\)

c: \(C=\left(6-2.8\right)\cdot\dfrac{25}{8}-\dfrac{8}{5}\cdot4\)

\(=\dfrac{16}{5}\cdot\dfrac{25}{8}-\dfrac{32}{5}\)

\(=5\cdot2-\dfrac{32}{5}=10-\dfrac{32}{5}=\dfrac{18}{5}\)

d: \(D=\left(\dfrac{-5}{24}+\dfrac{18}{24}+\dfrac{14}{24}\right):\dfrac{-17}{8}\)

\(=\dfrac{27}{24}\cdot\dfrac{-8}{17}=\dfrac{-9}{8}\cdot\dfrac{8}{17}=\dfrac{-9}{17}\)

Bài 6:

a) Ta có: \(A=-\frac{7}{12}+\left(1+\frac{1}{3}\right)\)

\(=-\frac{7}{12}+\frac{4}{3}\)

\(=-\frac{7}{12}+\frac{16}{12}\)

\(=\frac{9}{12}=\frac{3}{4}\)

b) Ta có: \(B=\frac{2}{15}+\left(\frac{5}{9}+\frac{-6}{9}\right)\)

\(=\frac{2}{15}-\frac{1}{9}\)

\(=\frac{6}{45}-\frac{5}{45}=\frac{1}{45}\)

c) Ta có: \(C=\left(-\frac{1}{5}+\frac{3}{12}\right)+\frac{-3}{4}\)

\(=\frac{-1}{5}+\frac{3}{12}+\frac{-3}{4}\)

\(=\frac{-12}{60}+\frac{15}{60}+\frac{-45}{60}\)

\(=\frac{-42}{60}=\frac{-7}{10}\)

8 tháng 8 2016

13/50+9/100+41/100+12/50

=(13/50+12/50)+(9/100+41/100)

=1/2+1/2

=1

23 tháng 8 2016

11) Ta có:

\(\frac{120-0,5.40.5.0,2.20.0,25-20}{1+5+9+...+33+37}\)

\(=\frac{120-\left(0,5.40\right).\left(5.0,2\right).\left(20.0,25\right)-20}{1+5+9+...+33+37}\)

\(=\frac{120-20.1.5-20}{1+5+9+...+33+37}\)

\(=\frac{120-100-20}{1+5+9+...+33+37}\)

\(=\frac{0}{1+5+9+...+33+37}=0\)