a.

\(\frac{2^7\times9^3}{6^5\times8^2}=\frac{2^7\times\left(3^2\right)^3}{\left(2\times3\right)^5\times\left(2^3\right)^2}=\frac{2^7\times3^6}{2^5\times3^5\times2^6}=\frac{3}{2^4}=\frac{3}{16}\)

b.

\(\frac{6^3+3\times6^2+3^3}{-13}=\frac{\left(2\times3\right)^3+3\times\left(3\times2\right)^2+3^3}{-13}=\frac{2^3\times3^3+3\times3^2\times2^2+3^3}{-13}=\frac{8\times3^3+3^3\times4+3^3}{-13}\)\(=\frac{3^3\times\left(8+4+1\right)}{-13}=\frac{27\times13}{-13}=-27\)

c.

\(\frac{5^4\times20^4}{25^5\times4^5}=\frac{\left(5\times20\right)^4}{\left(25\times4\right)^5}=\frac{100^4}{100^5}=\frac{1}{100}\)

d.

\(\left(\frac{5^4-5^3}{125^4}\right)=\frac{5^3\times\left(5-1\right)}{\left(5^3\right)^4}=\frac{5^3\times4}{5^{12}}=\frac{4}{5^9}\)

a)\(\frac{2^7.9^3}{6^5.8^2}=\frac{2^7.\left(3^2\right)^3}{2^5.3^5.\left(2^3\right)^2}=\frac{2^7.3^6}{2^5.3^5.2^6}=\frac{3}{2^4}\)

b)\(\frac{6^3+3.6^2+3^3}{-13}=\frac{6.6^2+3.6^2+3^3}{-13}=\frac{6^2.\left(6+3\right)+3^3}{-13}=\frac{6^2.9+3^3}{-13}=\frac{6^2.3^2+3.3^2}{-13}=\frac{3^2.\left(6^2+3\right)}{-13}=\frac{3^2.39}{-13}=3^2.\left(-3\right)=-27\)

c)\(\frac{5^4.20^4}{25^5.4^5}=\frac{100^4}{100^5}=\frac{1}{100}\)

làm nhanh giùm mình nha mình đang cần gấp

bài 1:

43/60.(-80/129)

=-4/9

bài 2:

3/12-2/12-24/12

4/12-3/12-24/12

=1/12(3-2-24)

  1/12(4-3-24)

=3-2-24 

  4-3-24

=-23/(-23)=1

\(\left[\frac{41}{75}+\frac{17}{100}\right]:\frac{-129}{80}=\left[\frac{41}{75}+\frac{17}{100}\right]\cdot\frac{-80}{129}\)

\(=\left[\frac{41\cdot4}{300}+\frac{17\cdot3}{300}\right]\cdot\frac{-80}{129}\)

\(=\left[\frac{164}{300}+\frac{51}{300}\right]\cdot\frac{-80}{129}\)

\(=\frac{43}{60}\cdot\frac{-80}{129}=\frac{1}{3}\cdot\frac{-4}{3}=\frac{-4}{9}\)

Bài 2 : \(M=\frac{\frac{1}{4}-\frac{1}{6}-2}{\frac{1}{3}-\frac{1}{4}-2}=\frac{\frac{1\cdot3}{12}-\frac{1\cdot2}{12}-\frac{8\cdot3}{12}}{\frac{1\cdot4}{12}-\frac{1\cdot3}{12}-\frac{8\cdot3}{12}}\)

\(=\frac{\frac{3}{12}-\frac{2}{12}-\frac{24}{12}}{\frac{4}{12}-\frac{3}{12}-\frac{24}{12}}=\frac{\frac{1}{12}\left[3-2-24\right]}{\frac{1}{12}\left[4-3-24\right]}=\frac{3-2-24}{4-3-24}=\frac{-23}{-23}=1\)

\(\frac{243^5.81^7.9^{15}.3^6.9^4.3^{18}}{9^8.729^8.81^9.27^5}=\frac{\left(3^5\right)^5.\left(3^4\right)^7.\left(3^2\right)^{15}.3^6.\left(3^2\right)^4.3^{18}}{\left(3^2\right)^8.\left(3^6\right)^8.\left(3^4\right)^9.\left(3^3\right)^5}=\frac{3^{25}.3^{28}.3^{30}.3^6.3^8.3^{18}}{3^{16}.3^{48}.3^{36}.3^{15}}=\frac{3^{115}}{3^{115}}=1\)

a)\(\frac{2}{3}+\frac{3}{4}+\frac{5}{6}\)

\(=\frac{8+9+10}{12}\)

\(=\frac{27}{12}=\frac{9}{4}\)

b)\(\frac{15}{8}-\frac{7}{12}+\frac{5}{6}\)

\(=\frac{45-14+20}{24}\)

\(=\frac{51}{24}=\frac{17}{8}\)

2)

a)\(\frac{2}{5}+\frac{7}{13}+\frac{3}{5}+\frac{1}{7}\)

\(=\frac{2}{5}+\frac{3}{5}+\frac{7}{13}+\frac{1}{7}\)

\(=1+\frac{7}{13}+\frac{1}{7}\)

\(=\frac{20}{13}+\frac{1}{7}\)

\(=\frac{153}{91}\)

Tí tớ trả lời tiếp

\(A=\left(\dfrac{1}{x^2-4x}+\dfrac{2}{16-x^2}+\dfrac{4}{4x+16}\right):\dfrac{1}{4x}\left(x\ne4;x\ne-4;x\ne0\right).\)

\(A=\left(\dfrac{1}{x\left(x-4\right)}+\dfrac{-2}{\left(x+4\right)\left(x-4\right)}+\dfrac{1}{x+4}\right).4x\).

\(A=\dfrac{x+4-2x+x^2-4x}{x\left(x-4\right)\left(x+4\right)}.4x.\)

\(A=\dfrac{x^2-5x+4}{\left(x-4\right)\left(x+4\right)}.4.\)

\(A=\dfrac{\left(x-4\right)\left(x-1\right)}{\left(x-4\right)\left(x+4\right)}.4.\)

\(A=\dfrac{4\left(x-1\right)}{x+4}.\)

chịch ko em

Bài 1 

\(=-\frac{21}{60}=-\frac{7}{20}\)

\(b,\left(2-\frac{1}{3}\right)^2+|-\frac{5}{6}|+\frac{-7}{12}-\frac{25}{9}\)

\(=\frac{25}{9}+\frac{5}{6}-\frac{7}{12}-\frac{25}{9}\)

\(=\left(\frac{25}{9}-\frac{25}{9}\right)+\left(\frac{5}{6}-\frac{7}{12}\right)\)

\(=0+\frac{1}{4}=\frac{1}{4}\)

Bài 2

\(a,x+\frac{2}{5}=-\frac{3}{10}\)

\(x=-\frac{3}{10}-\frac{2}{5}\)

\(x=-\frac{3}{10}-\frac{4}{10}\)

\(x=-\frac{7}{10}\)

\(b,|\frac{2}{3}+x|=\frac{5}{7}\)

\(\Rightarrow\orbr{\begin{cases}\frac{2}{3}+x=\frac{5}{7}\\\frac{2}{3}+x=-\frac{5}{7}\end{cases}\Rightarrow\orbr{\begin{cases}x=\frac{5}{7}-\frac{2}{3}\\x=-\frac{5}{7}-\frac{2}{3}\end{cases}\Rightarrow}\orbr{\begin{cases}x=\frac{1}{21}\\x=-\frac{29}{21}\end{cases}}}\)

==  chắc trog quá trình lm lỡ xóa đó 

\(a,-\frac{3}{4}.\frac{7}{15}\)

\(=-\frac{21}{60}=-\frac{7}{20}\)

với lại bài trên mk tính nhẩm ko bấm máy sai == sửa giúp