a: \(=\dfrac{13\left(3-18\right)}{40\left(15-2\right)}=\dfrac{13}{15-2}\cdot\dfrac{-15}{40}=\dfrac{-3}{8}\)

b: \(=\dfrac{18\left(34-124\right)}{36\left(-17-13\right)}=\dfrac{1}{2}\cdot\dfrac{-90}{-30}=\dfrac{3}{2}\)

c: \(=\dfrac{3\left(\dfrac{1}{41}-\dfrac{4}{47}+\dfrac{9}{53}\right)}{4\left(\dfrac{1}{41}-\dfrac{4}{47}+\dfrac{9}{53}\right)}+\dfrac{\dfrac{-1}{4}\cdot\dfrac{-2}{3}-\dfrac{3}{4}:\dfrac{1}{6}}{\dfrac{3}{2}\cdot\left(\dfrac{-2}{3}-\dfrac{3}{4}\cdot\dfrac{-2}{3}\right)}\)

\(=\dfrac{3}{4}+\dfrac{\dfrac{2}{12}-\dfrac{9}{2}}{\dfrac{3}{2}\cdot\dfrac{-1}{6}}=\dfrac{3}{4}+\dfrac{-13}{3}:\dfrac{-3}{12}=\dfrac{3}{4}+\dfrac{13}{3}\cdot\dfrac{12}{3}\)

\(=\dfrac{3}{4}+\dfrac{156}{9}=\dfrac{217}{12}\)

kết quả = 3/2

\(A=\frac{8\frac{3}{9}\cdot5\frac{1}{4}+3\frac{16}{19}\cdot5\frac{1}{4}}{\left(2\frac{14}{17}-2\frac{1}{34}\right)\cdot34}:\frac{7}{24}\)

\(A=\frac{\left(8\frac{3}{9}+3\frac{16}{19}\right)\cdot5\frac{1}{4}}{\left(2\frac{14}{17}-2\frac{1}{34}\right)\cdot34}\cdot\frac{24}{7}\)

\(A=\frac{\left(\frac{25}{3}+\frac{73}{19}\right)\cdot\frac{21}{4}}{\left(\frac{48}{17}-\frac{69}{34}\right)\cdot34}\cdot\frac{24}{7}\)

\(A=\frac{\frac{694}{57}\cdot\frac{21}{4}}{\frac{27}{34}\cdot34}\cdot\frac{24}{7}=\frac{\left(\frac{2429}{38}\right)}{27}\cdot\frac{24}{7}=\frac{1388}{171}\)

P/S : Số lớn quá

\(\dfrac{2}{1.4}x+\dfrac{2}{4.7}x+\dfrac{2}{7.10}x+...+\dfrac{2}{31.34}x=10\)

\(=>1,5.\left(\dfrac{2}{1.4}x+\dfrac{2}{4.7}x+\dfrac{2}{7.10}x+...+\dfrac{2}{31.34}x\right)=15\)

\(=>\dfrac{3}{1.4}x+\dfrac{3}{4.7}x+\dfrac{3}{7.10}x+...+\dfrac{3}{31.34}x=15\)

\(=>x\left(\dfrac{3}{1.4}+\dfrac{3}{4.7}+\dfrac{3}{7.10}+...+\dfrac{3}{31.34}\right)=15\)

\(=>x\left(1-\dfrac{1}{4}+\dfrac{1}{4}-\dfrac{1}{7}+\dfrac{1}{7}-\dfrac{1}{10}+...+\dfrac{1}{31}-\dfrac{1}{34}\right)=15\)

\(=>x\left(1-\dfrac{1}{34}\right)=15\)

\(=>\dfrac{33}{34}x=15\)

\(=>x=\dfrac{170}{11}\)

\(=\dfrac{2^{12}\cdot3^{10}+2^{12}\cdot3^{10}\cdot5}{2^{12}\cdot3^{12}-2^{11}\cdot3^{11}}=\dfrac{2^{12}\cdot3^{10}\cdot6}{2^{11}\cdot3^{11}\cdot5}=\dfrac{2}{3}\cdot\dfrac{6}{5}=\dfrac{4}{5}\)

a: \(=\dfrac{\left(5^3\right)^3\cdot4^4}{5^{12}}=\dfrac{1}{5^3}\cdot4^4=\dfrac{4^4}{5^3}\)

b: \(=\dfrac{3^6}{\left[3^3\cdot2\right]^2}=\dfrac{1}{2^2}=\dfrac{1}{4}\)

c: \(=\dfrac{2^{12}\cdot3^{10}+2^{12}\cdot3^{10}\cdot5}{2^{12}\cdot3^{12}-2^{11}\cdot3^{11}}\)

\(=\dfrac{2^{13}\cdot3^{11}}{2^{11}\cdot3^{11}\cdot5}=\dfrac{4}{5}\)

        \(\frac{4^6.9^5+69.120}{8^4.31^2-6^{11}}\)

<=>-0,67

giải giúp mình chi tiết nhé!!!!!!

\(\frac{4^6.9^5+69.120}{8^4.31^2-6^{11}}=\frac{2^6.2^6.3^5.3^5+3.23.2^3.3.8}{\left(8^2\right)^2.31^2-\left(2.3\right)^{11}}\)

\(=\frac{2^6.2^6+3^5.3^5+3.23.2^3.3.8}{16^2.31^2-2^{11}.3^{11}}\)

\(=\frac{4^6.3^5.3^5+3.23.2^3.3.8}{\left(4^2\right)^2.31^2-2^{11}.3^{11}}\)

\(=\frac{4^6.3^5.3^5+3.23.2^3.3.8}{4^4.31^2-2^{11}.3^{11}}\)

Tới đây bạn tự làm nha.

\(A=\)\(\frac{4^6.9^5+6^9.120}{6^{11}+8^4.3^{12}}\)

\(A=\frac{2^{12}.3^{10}+6^9.6.2^2.5}{6^{11}+2^{12}.3^{12}}\)

\(A=\frac{2^{12}.3^{10}+6^{10}.2^2.5}{6^{11}+2^{12}.3^{12}}\)

\(A=\frac{2^{12}.3^{10}+2^{10}.3^{10}.2^2.5}{\left(2.3\right)^{11}+2^{12}.3^{12}}\)

\(A=\frac{2^{12}.3^{10}+2^{12}.3^{10}.5}{2^{11}.3^{11}+2^{12}.3^{12}}\)

\(A=\frac{2^{12}.3^{10}.\left(1+5\right)}{2^{11}.3^{11}.\left(1+2.3\right)}\)

\(A=\frac{2^{12}.3^{10}.6}{2^{11}.3^{11}.7}\)

\(A=\frac{2^{12}.3^{10}.2.3}{2^{11}.3^{11}.7}\)

\(A=\frac{2^{13}.3^{11}}{2^{11}.3^{11}.7}\)

\(A=\frac{2^2}{7}\)\(=\frac{4}{7}\)